Notes on timing belt maintenance for 1990 Honda Accord

This job can be a little harder than it needs to be, especially if you are missing parts of your brain like me. Here is a list of things to watch out for.

Removing crankshaft center bolt

This can be difficult because of how much torque is used to correctly tighten this bolt. I could not remove it with a 1/2 impact wrench. A better idea is to use the correct crankshaft pulley tool to prevent the crankshaft from rotating, while using a large breaker bar or jack handle to break the bolt loose.

When reinstalling this bolt, coat the threads with red loctite and torque it completely. I had used blue loctite and it came loose a few months later. Also when reinstalling, check the key and crankshaft pulley keyway for damage and replace as necessary.

Oil seals

Be sure to replace all four front engine oil seals while you are in here. It’s somewhat easy to do and you’ll just end up with oil leaks from brittle seals if you don’t. The easiest tool to use to pop out old seals is a paint can opener.

If there is a mess inside the timing cover from oil leaks, use Simply Green cleaner, water, a large toilet or bottle-style brush, and rags.

To install the camshaft and front balance shaft seals evenly, use a piece of 1 1/4″ PVC pipe that is cut appropriately short.

A front balance shaft seal retainer can be purchased from Honda or comes as part of timing belt kits like this one, so don’t forget to install it or the seal might pop out.

To remove and install the front balance shaft pulley, which is required to change the oil seal, the front balance shaft has a through hole. Stick a screwdriver through it and wedge the screwdriver against something else. Use blue loctite when reinstalling.

When reinstalling the crankshaft timing pulley after changing the seal, there is a belt guard plate that has dimples in it. The plate should be installed with the dimples protruding towards the engine so that they do not rub against the timing belt.

The camshaft timing pulley can be removed and installed to change the seal by wedging a screwdriver through the pulley itself and then breaking loose the bolt or torquing it. When removing the camshaft pulley, don’t lose the small metal key or you’ll have to buy a new one. When installing, use blue loctite.

The rear balance shaft has a hole in it to identify TDC. There is a plug on the rear of the engine that has to be removed to access it. Then stick a screwdriver in while rotating the rear balance shaft until the point where the screwdriver goes in the deepest and locks it. After it is locked, mark the position of the rear balance shaft pulley and then remove the pulley and the oil pump cover it attaches to. When reinstalling with a new O-ring seal, ensure that the shaft is still locked to TDC and that the pulley mark lines up. Use a very small amount of RTV on the new O-ring seal only to keep it in place while installing the pulley and cover.

Putting things back together

BEFORE you install the new timing belt, reinstall the inner timing cover behind the camshaft timing pulley, or you will be unhappy later.

The water pump has five screws. Four are obvious, and one is disguised as the post for the balance shaft tensioner spring.

Don’t RTV the whole water pump seal. Use only a small amount to keep the seal in place while installing. Honda also recommends using RTV to seal the rubber foot on the bottom towards the rear of the engine. I guess this is to ensure that if the water pump weeps, it drips externally instead of onto the timing belt.

Installing the timing belt

You can reuse the timing belt tensioner if it turns smoothly, but in any case, use replacement springs since they will lose their tension over time. Tensioner springs should be positioned so that they do not interfere with the tensioner itself however it would pivot while the belt is being tensioned. Just play around with it and ensure no obstruction.

When installing the timing belt tensioner, a timing cover screw should be TEMPORARILY installed into the hole to the left of the tensioner (through the tensioner slot) to hold the tensioner down. The reason for this is so that the tensioner does not fall off the small pivot pin on the right while installing the belt and other components. If the tensioner falls off this pin, it will be impossible to tension the timing belt correctly.

The temporary screw should be REMOVED once the hold down nut is installed at the end on the tensioner mounting stud and the slotted arm of the timing belt tensioner should then slide freely up and down, flush against the engine block.

Get a replacement tensioner hold down nut from Honda since your dome-style nut is probably rounded off by now. The replacement has flats all the way to the top of the nut to reduce the risk of rounding it.

To tension the balance shaft belt, slightly loosen the pivot bolt in the middle of the tensioner arm, then re-tighten to 84 lb-in (9 lb-ft).

To tension the timing belt, follow the instructions in the manual. Summary: loosen the tensioner hold down nut, turn the crankshaft counterclockwise a few notches, and then re-tighten the nut.

Test it before buttoning everything up

This will save you a lot of aggravation if you got anything slightly wrong. Just set the tension, set the valve cover back in place to prevent oil splatter, and tighten the crankshaft bolt into the timing pulley by hand, leaving off the crankshaft accessory pulley. You can start and run the motor this way and check for leaks, proper belt tension, and any other problems without potentially wasting a lot of time if you had gotten something slightly wrong in assembly.

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