My 1991 ACTY SDX next to a 2012 Ford F250 truck.
1989-1997 Honda ACTY Truck & Van Info
By Rob Robinette
Have comments or corrections? Email rob at: robinette at comcast dot net
I purchased my ACTY mini-truck in January 2019 and couldn't be happier with the little guy. The ACTY, short for "activity", is a Japan domestic market (JDM) mini-truck and mini-van that was never imported into the United States but US importers are now bringing used trucks and vans into the USA and people are snapping them up. Their all wheel drive makes them perfect for a working farm or ranch. I'm amazed that my mini truck will crawl around my farm and yet easily cruise at 60 miles per hour on the highway. I also like the right-hand drive and manual 5 speed transmission. Shifting with my left hand is fun. This truck gets a lot of attention. People stare, wave and chase me down to ask questions.
This page is a work in progress. As I do more work on my truck I'll add info and pictures. So far I have changed the engine oil, oil filter, transmission oil, front differential oil, air filter, coolant, spark plugs and put on new tires. I also plan to change the front brake pads & brake discs, rear brake shoes, turn the rear drums, flush the brake fluid, replace the fuel filter, timing belt & water pump.
If you're going to do a lot of your own maintenance I highly recommend the ACTY Honda English Factory Service Manual. It covers the 89 to 97 ACTY van and truck.
My 1991 Honda ACTY truck is an HA4 model with a three cylinder, 39 horsepower, 40.5 lb-ft torque, 40.2 cubic inch (660cc, .66 liter) EO7A Engine.
Table of Contents
The VIN Number (frame number) is located beneath the driver seat.
The engine and transaxle (transmission+rear differential) is located under the truck bed, forward of the rear axle. There is an engine access panel in the center of the truck bed.
Sticker on back of truck says 350 kg cargo capacity (772 lbs).
PSI: 26 front, 29 rear
With two people and more than 100kg of cargo (220lbs): 29 front, 34 rear
Bar: 1.8 front, 2.0 rear, With two people and more than 100kg of cargo (220lbs) 2.0 front, 2.4 rear
Tire Air Pressure Label
Tire pressure label on the driver door frame. Pressure in kg/cm2=kilogram per cubic centimeter=BAR. Factory tires are listed as 5 inch section width on 12 inch diameter rims & 4 ply radial ultra-light truck (22x4x12) or 145mm section width on 12 inch rims 6 ply radial light truck (145/80R12). The yellow sticker on the bottom denotes an engine oil change.
Spare Tire: In the truck it's located under the bed/cab below the passenger seat.
Fuel Tank: 9.8 gallons or 37 liters
Jack Points: The manual says you can jack the truck from the front and rear axle beams. There are also two metal protrusion jack points at the extreme front corners. The rear leaf suspension forward mounts (just forward of the rear wheels) are also approved jack points.
Towing: Four wheel drive ACTY's should not be towed over 25mph (40kph) or for long distances. The towing attachment hook is located below the front bumper license plate holder. Make sure the parking brake is released and the transmission is in neutral.
Do all the oil changes after a drive to warm up the engine, transmission and differential oils.
Engine Oil: 10w30 3 quarts (2.9 liter) when changing the filter, 2.8Q (2.7L) when not changing the filter. If operating in temperatures below -22 degrees F (-30C) then use 5w30 oil and change oil every 3 months. The Factory Manual says to change the oil every 10,000km (6,250 miles) or every six months. Since my truck has over 100,000km on the odometer I use Castrol High Mileage Synthetic Blend 10w30 for both the engine and manual transmission. The oil dipstick is in the left rear wheel well.
Engine Oil and Manual Transmission Drain and Fill Bolts
Oil drain bolt at lower left, oil filter at lower center. Torque the engine oil drain bolt to 3.5-4.5 kgm.
Oil Filter: I recommend the Bosch 3323 (2006 Honda Civic 1.8 oil filter), NAPA 27356 and WIX 57356 are tall filters for max life. The following short filters are the same size as the factory Honda part: (NAPA 1334 or NAPA Gold 1358), Bosch 3312, Fram PH9688, filter thread size: M20x1.5. Put clean oil on the oil filter gasket and threads before installation.
The dipstick is behind the tire. The coolant reservoir has been removed for cleaning but it hangs on the left side of the battery box. Note these are new Nanking CX668 155/80R12 tires.
5 Speed Manual Transmission: MTF or API SE 10w30 oil 1.3 quart (1.2L). I like to put a little fresh oil in with the drain bolt still out to flush out the bottom of the transmission case. Replace the drain bolt and put a nozzle on the oil bottle and squeeze it into the fill hole until it starts to run out of the fill hole.
Manual Transmission Fill & Drain Bolts
Manual Transmission fill and drain bolts. A 3/8 inch ratchet wrench fits into the square hole in the transmission drain bolt. Do not drain the transmission until you get the fill bolt loose. I had to use a large breaker bar to get the transmission and front differential drain and fill bolts loose. I could not find torque specs for the manual transmission and front differential fill and drain bolts but 7kgm is a good guess.
Front Differential: API GL-4 75w85 gear oil 0.48 quart. I use Lucas GL-4 GL-5 full synthetic 75w90 gear oil. GL-5 meets or exceeds GL-4 specs. I like to put a little fresh oil in with the drain bolt still out to flush out the bottom of the differential case. Replace the drain bolt and put a nozzle on the oil bottle and squeeze it into the fill hole until it starts to run out of the fill hole.
Front differential fill and drain bolts. A 3/8 ratchet wrench fits into the square hole in the differential drain bolt. Do not drain the differential until you get the fill bolt loose. I had to use a large breaker bar to get the transmission and front differential drain and fill bolts loose. I could not find torque specs for the manual transmission and front differential fill and drain bolts but 7kgm is a good guess.
Tires: Stock tires are LT145/80R12 6 ply radial (Light Truck 21.2" diameter, 145mm section width, 80 profile, 12 inch diameter wheel rim) and optional 155/70R13 (21.5")
Nankang CX668 155/80R12 (21.8" diameter), wear rating 440, M+S (mud & snow rated) $35 each on Amazon, $259 for 4 at Discount Tire installed, fit and drive great on the stock 12" wheels. I put these on my truck and I really like them for highway use.
Sun F All 22x7x12 off road tires fit stock wheels Amazon $61 each shipped.
Wheels: Stock are 4x100 lug pattern, 12x3.5" (12 inch wheel diameter and 3.5 inch width) or 13x4", 56.1mm center bore hole
The stock wheels have 100mm (3.937") of backspacing and with stock tires have about 1" clearance to the coil springs.
Wheel Adapter: Allows more common 4x114.3 wheels to be fitted. Four 1" (25mm) thick Wheel Adapter Spacers 4x100 to 4x114.3 with M12x1.5 lugs, Amazon $58. These adapters add 1 inch of positive offset and 1" backspacing.
With 1" 4x114.3 adapter, 14x7 +13 offset Fuel Maverik wheels and 23x9.5x14 inch tires fit.
14x6 +30 offset with 175/65/14 tires fit with no lift and no rubbing.
2 inch Lift Kit: Available for $200 on ebay allows the use of larger diameter wheels and tires but also raises the vehicle's center of gravity making it even more prone to tip over. The kit has 2 inch spacers to lower the front struts. In the rear a 4 inch longer spring leaf mount is used on one end of the leaf springs for 2 inches of lift. A 3 inch lift kit is available but extensive modifications must be done to make it fit and it is not recommended.
Brakes: Front brake pads and discs for the 89 Civic did not fit my 91 ACTY. The front brake pads for a 92 Honda Civic may fit the HA4 ACTY. CarQuest part number FRI B576. CarQuest is now part of Advance Auto Parts.
Front brake caliper and disc. Remove the caliper release bolt and swing the caliper up to replace brake pads. After installing new, thick brake pads you'll have to use a c-clamp to compress the brake caliper piston to be able to swing the brake caliper over the new pads. To remove the brake disc you must remove the caliper and the two screws holding the disc in place. The two brake disc screws can be easily removed by using an impact driver (hammer screwdriver).
Brake Fluid: The brake master cylinder is located behind a pop-off access panel on the right end of the driver's dashboard. Open the driver door and you'll see the panel on the side of the dash board. The manual says to use DOT 3 or 4 brake fluid. I prefer DOT 4. The brake bleed order is right rear, left rear, right front, left front. If you do a complete flush use a mechanic's syringe to suck out as much of the old fluid from the reservoir as possible, then fill it with fresh brake fluid and bleed the brakes. Do not allow the reservoir to get low and suck air into the brake system during bleeding.
Brake Master Cylinder/Reservoir Access
The brake master cylinder and reservoir are just behind the access panel. It pops off with a pull.
Air Filter: A840J $37 ebay. Also Toyo TO-3670 and NKK 4HM-1046. Located at the rear of the truck above the exhaust. There are three spring clips that hold the air filter cover in place. After removing the cover remove the wing nut holding the filter in place.
Air Filter at the back of the truck.
Fuel Filter: Service manual says change every 24,855 miles (40,000km). Use pliers to move the fuel line clamps away from the filter and remove both fuel lines. A wide flat-blade screwdriver can be used to push the fuel lines off the filter. Push the filter up and out of its retainer and install the new filter.
Fuel System Components
Fuel pump and fuel filter under the truck bed. Note the fuel tank at bottom right. The small fuel 2-way valve above the filter may have to be moved to get the filter up and out of its retainer.
Flushing the Cooling System
Coolant: 5.3 quarts (1 gallon and 1.3 quarts or 5 liters) total. With automatic transmission 7.1 liters. Van with rear heater 6.7 liters. Van with rear heater and automatic transmission 7.4 liters. Manual says to use 30% coolant (1.6 quarts, 1.5 liters) and 70% distilled water (3.7 quarts, 3.6 liters). Honda Type 2 or standard auto parts store coolant (ethylene glycol). For cold climates I recommend 50% coolant.
Turn the cab heater control to full hot so the coolant in the heater will be flushed. The radiator is at the front of the truck, down low behind the front bumper. The radiator cap is in the cab, on the passenger side, on the firewall. It has a cover that's held in place by a wing nut (see photo below). Remove the nut and remove the cover to gain access to the cap. The radiator drain cock is on the bottom of the radiator, driver side, pointing rearward. The drain cock is just above a small square drain hole in the lower bumper. It has two "wings" to help you turn it. The manual says to replace its o-ring anytime the drain cock is opened. There is also an engine block drain bolt just above the oil filter. Remove it to drain the coolant from the engine.
Engine Block Coolant Drain Bolt
Engine block coolant drain bolt is just above the oil filter. Replace the crush washer and torque to 4-5kgm. Squeeze the large coolant hoses to help "burp" air out of the cooling system.
The coolant reservoir is next to the battery. It can be lifted out of its mounting slot. In the ACTY van the coolant reservoir slides out for access. Remove the cap by popping it off (it does not screw off) and flush out the reservoir with water then empty it. Fill it to the "MAX" line with coolant, replace the cap and slide it into its mounting bracket.
Filling the Radiator
Use a flexible funnel or you'll make a huge mess.
After draining the old coolant, replace the engine block drain bolt (torque to 4-5kgm) and tighten the radiator drain cock finger-tight. Use a long neck flexible funnel to add 1.6 to 2 quarts of undiluted coolant then fill the radiator with distilled water. If you use pre-diluted 50/50 coolant then fill the radiator and reservoir with that--do not add any distilled water. Put the radiator cap on, turn the cab heater control to full hot and run the engine until the low idle kicks in which means the engine is warm and the thermostat is open flowing coolant through the radiator and heater.
Drain petcock is just above the square drain hole in the front bumper. Rapidly squeeze and release the large coolant hose to burp the cooling system.
Bleeding the Cooling System: It is important to remove air bubbles in the cooling system to prevent engine hot spots. With the truck running, rapidly squeeze and release the large coolant hoses at the bottom of the engine (near the battery box) and at the bottom of the radiator to "burp" the system and move air bubbles to the reservoir and to the top of the radiator. Shut off the engine and allow it to cool, then top off the radiator with pre-mix coolant or distilled water. The Factory Manual also says to "Shut off the engine and shake the vehicle to release air bubbles." Run the engine and repeat the burping and shaking one more time then with the engine still running, open the four bleeder bolts, one at a time, until coolant comes out then close them immediately (see next two photos below).
Coolant Line Bleeder Bolts
Bleeder bolts (10mm) in the rigid coolant lines above the spare tire (remove spare tire for access). Open them to allow air bubbles to escape. Torque them to 1.8kgm.
The four bleed bolts allow us to remove air bubbles high in the coolant system. There are two or three bleeder bolts on top of the engine (12mm) which must be accessed by removing the access panel in the center of the truck bed (four 14mm bolts). There are also two bleeders on the rigid coolant lines just above the spare tire (see photo above). Remove the spare tire and use a 10mm wrench to open them until coolant comes out then close them. Check the radiator drain cock and engine block drain bolts for leaks.
Engine Access Panel Removed For Coolant Bleeders
Bleeder bolts in the engine bay take a 12mm wrench or socket. Coolant will come out of the bolt center hole when air is bled. Open them to allow air bubbles to escape. If your ACTY has an automatic transmission there will be a third bleeder bolt on the transmission fluid cooler above the engine. Note the spark plug caps at far left.
Check the coolant reservoir and add coolant if it is below the "MIN" line. Before your next drive with the engine cold, top off the radiator once again with distilled water. With the engine cold, check the coolant reservoir and add or remove coolant to get the level between "MIN" and "MAX" lines.
Thermostat: The thermostat is inside the thermostat housing on the bottom of the engine block where two large coolant hoses connect to the engine (see photo below). The thermostat cover is held in place with three bolts (torque to 1kgm). Always replace the thermostat housing o-ring when the housing is removed. Top off the coolant after the thermostat replacement and run through the cooling system bleed procedure in the coolant flush section above. Also check for leaks after the engine is warm. After the engine cools top off the radiator again. Honda ACTY thermostats can be purchased at O'reilly Auto Parts. The part number is 3758 and costs about $6 for a 1990 ACTY.
Water Pump: The water pump is located at the bottom of the engine under the timing belt cover (it is driven by the timing belt). There are two small weep holes in the timing belt cover. If any coolant comes out of the weep holes the water pump must be replaced. It should also be replaced when the timing belt is replaced at 100,000km. Always replace the water pump o-ring when replacing the pump. You must remove the timing belt, timing belt idler and lower cover to gain access to the pump so you might as well replace the timing belt, timing belt tensioner and idler at the same time. Torque the idler bolt to 4.5kgm. There are four bolts holding the pump cover in place. Torque them to 1kgm.
Timing Belt: Manual says to replace no later than 100,000km (62,000 miles). If you replace the alternator belt at 68,000km then go ahead and do the timing belt too. Also replace the timing belt tensioner, idler pulley, water pump and water pump o-ring, alternator belt and air conditioning compressor belt at the same time. Order the parts from the parts suppliers below. You can order a timing belt "kit" with belt, tensioner, idler, water pump and pump o-ring.
To replace the belt you have to remove all the belt covers on the passenger side of the engine. You also have to remove the passenger side engine mount. Raise the engine slightly with a jack (place rubber pad or rag on the jack to prevent oil pan damage) and remove the engine mount. Use a wrench on the crankshaft pulley bolt to turn the engine counter-clockwise to set the #1 cylinder at top-dead-center by aligning the TDC marks on the crankshaft pulley and engine block, and with the "UP" label on the cam sprocket up. Make note of this position so you can set it when you install the new timing belt. Loosen the timing belt tensioner bolt 1/6th of a turn and slide the timing belt off. Remove and replace the timing belt tensioner and idler pulley. Remove and replace the water pump and water pump o-ring. Replace the timing belt and carefully verify the position of the crankshaft and camshaft pulleys. Torque the idler pulley and tensioner bolts to 4.5kgm. If your ACTY won't start or runs rough after the timing belt replacement the belt may be out of position. Set the #1 cylinder to TDC and verify the timing marks on the crankshaft pulley and cam sprocket.
Alternator Belt: 10mm x 675mm long which is a standard size available at auto parts stores. Manual says to replace at 68,000km (42,000 miles). There is a large inspection grommet on the belt cover to check condition and tightness. Belt tightness should be checked with a gauge at 20-30kgf and 9-12mm of travel. Torque the alternator adjustment bolt to 2.5kgm and the alternator pivot bolt to 4.5kgm.
Air Conditioning Compressor Belt: Replace at 68,000km (42,000 miles, same as alternator belt). Check AC fluid when replacing the belt. New belt tension 35-60kgf, used belt 22-40kgf.
Japanese Parts Suppliers who ship worldwide:
Another source but typically more expensive: http://jp-carparts.com/honda
Spark Plugs: Need 3, NGK BKR6E-11 (recommended), ND K20PR-U11 or Champion Iridium 9001, Spark Plug Gap: 1 - 1.1 mm. Access the spark plugs by removing the truck bed engine access panel by removing its four 14mm bolts (see engine photo above). Remove the throttle cable support bracket (one 10mm bolt) to give you room to get the #2 spark plug wire off.
Windshield Wipers: Standard auto parts store 15" wipers are perfect.
Clutch Pedal: Stroke 130-135mm, Backlash 15-25mm, Gap to Floor not less than 79mm.
Fuse Box: Is mounted on the firewall under the dash to the left of the steering wheel.
My 91 ACTY HA4 does not have air conditioning so the "Condenser Fan" and "AC" (top right) fuses are empty. These two fuses may be attached at lower left in some ACTY's. The "Rear Heater" fuse (center) and "Rear Defroster" (top left) are van only.
Radio: Standard 1 DIN replacement radio will slide right in. There are two 8mm bolts securing the radio bracket that you get to by removing the ashtray. They are in the top of the ashtray compartment and go up into the radio bracket. The 8mm bolts have a Phillips Head slot for a screwdriver but you'll probably need an 8mm socket wrench to remove them.
8mm socket on one of the radio bolts. The wrench goes through a hole in the ashtray bracket to access the bolts.
My ACTY's radio electrical plug has 4 conductors: switched 12v, ground and left speaker + & -. Some ACTY's come with a 6 conductor radio plug. The antenna connector is to the right of the electrical plug.
Radio Connector and Wires
The large connector's yellow with red stripe wire is switched 12v, black is ground, the blue is left speaker +, gray with black stripe is left speaker -. The small connector's white wire with blue stripe is unswitched 12v and the red with black strip is 12v instrument panel lights. My 91 ACTY HA4 did not have the right door speaker wires present. If your ACTY has a 6 conductor radio plug then the small 2 conductor plug will have your right door speaker wires (red and brown).
There is one speaker in the passenger door. There is a place to mount a second speaker in the driver door. If your ACTY has the right door speaker wire (mine did not) it is located behind the brake master cylinder which is located behind a pop-off access panel on the right end of the driver's dashboard (see photo below). Open the driver door and you'll see the panel on the side of the dash board. You'll have to un-bolt the brake master cylinder/reservoir to get to the wire. It is taped to another wire bundle. After cutting the tape that holds down the speaker wire it will be long enough to splice in more wire to make the run to the new right door speaker. To get to the speakers you have to remove the door panel screws and pull the glued panel away from the door. Be aware the stock speakers are very shallow. If your new speakers are much deeper than stock you'll have to add a ring to move the speaker out away from the window track.
To get to the right stereo channel speaker wire remove the brake master cylinder access door by pulling it off then unbolt the master cylinder to give you room to reach behind it and access the wire which is taped to another wire bundle.
My new radio required a constant, unswitched 12v source for memory retention so I used the small connector's white with blue stripe wire. On a related note, I wanted the cigarette lighter to switch off with the key so I changed its power supply to the radio's yellow-red wire. WARNING: The cigarette lighter will no longer be able to heat the actual cigarette lighter because it will pull more power than the radio wire can handle. I don't smoke so the lighter receptacle will only be used to power a GPS or a USB power converter which will power down when the key is turned off.
Honda "Real Time 4WD": The rear wheels normally drive the truck. When the rear wheels begin to slip the transaxle sends torque to the front wheels.
2/4 Wheel Drive Selector: On the drivers side where the front drive shaft (propeller shaft) enters the transmission, there is a 10mm locking bolt that holds a 10mm selector bolt (10mm bolt with a 30mm shoulder). There are two notches in the bolt shoulder. Rotate the bolt with the shoulder half a turn to select 2 wheel rear or 4 wheel drive. Tighten the lock bolt. The propeller shaft and front drive shafts will still be turned by the rotation of the front wheels but no engine torque will be sent to the front wheels. One ACTY owner reported his gas mileage went up by 3 miles per gallon in 2 wheel drive. Another ACTY owner reported a smoother ride with less vibration after switching to 2 wheel drive. Rumor has it that not all ACTYs have this selector bolt.
Loosen the Lock Bolt then turn the Selector Bolt 180 degrees to change from 2 wheel drive to 4 wheel drive and back.
Engine Bay From Driver Side
Engine bay view from other side of the truck.
1989 to 1997 ACTY Specifications
Idle Speed: 950 <> 1000 RPM
Fast Idle: 2200 to 3200
CO@ 3000 RPM <= 0.1
Oil Pressure: 55 to 64 PSI, 3.8 to 4.4 BAR
Fuel Pressure: 1 to 2 PSI, 0.07 to 0.14 BAR
Fuel 9.8 gallons, 37 liters of regular, low octane gasoline.
Reported Gas Mileage: Ranges from 35 to 53 miles per gallon (15 to 22.5 kilometers per liter)
Engine Compression: 14 BAR (203 PSI) at 250 RPM (normal starter spin rate) with 9.5 BAR (138 PSI) minimum, max difference between cylinders of 2 BAR (29 PSI). If compression is low adjust the valves and try again.
Valve Clearance Cold: Intake 0.18 to 0.22mm, Exhaust 0.25 to 0.29mm
CO@ 3000RPM => 0.1%
HC@ 3000RPM => 200 PPM
Coil resistance: 1.78 to 2.08 ohms
Trem 15(+): 12V
Ignition Timing: Manual Transmission 4 deg +/-2 deg at 1000 RPM, Automatic Transmission at 1150 RPM
Centrifugal advance: 0 @ 0 to 1400
18 to 22 @ 2400 to 2600
28 to 32 @ 5500
Vacuum range: 73 to 307 millibar
Front: Toe in: In 1mm +/-3 mm
Camber: HA3 +1 deg +/- 1 deg, HA4 +1.2 deg +/- 1 deg, HA4 & HH4 +1.3 deg +/- 1 deg
Caster: HA3, HA4, HH4 2.3 deg +/- 1 deg; HH3 2.5 deg +/- 1 deg
King Pin Incline: +12 deg 30'
Rear: Toe in: 0 +/-3 mm (rear is not adjustable)
Camber: 0 (rear is not adjustable)
Parking Brake: 44 lb (20 kg) pull in the 8 to 12th notch.
Brake Pedal: Height from floor 145 mm, Backlash 1-10 mm.
Front Brake Disc: 10 mm minimum thickness
Brake Pads: 3 mm minimum thickness
Rear Brake Drum: 2 mm minimum lining thickness