Today we are looking at what is involved in replacing the Timing Belt and/or Waterpump on the trusty old L series Toyota Diesel engines. Before we start I want to stress that although this information is supplied in good faith and is a step by step breakdown of me actually doing the job on a customers vehicle, we are dealing with valve, injector pump and piston timing here and if you are in any doubt that you may not have the skills and/or tools to complete the job then please leave it to a qualified mechanic.
Given that engine damage is also possible from faulty components it’s a good idea to stick with the known brands for replacement parts such as Dayco or Gates as found on EBAY.. Both of these brands are widely used in the repair industry and have a good name.
That being said, it is not a particularly difficult job to do but I urge you to read and understand all instructions in the article before starting to avoid any potential dramas. Part Two – Reassembly, can be found HERE.
The job doesn’t require too many ‘specialized’ tools, but here is a run down of the tools I’ve needed so far –
- The usual assortment of spanners and a good socket set (namely 10, 12, 14 and 19mm)
- Assortment of flat blade screwdrivers
- Small lever bar
- 1/2 inch drive breaker bar and 19mm socket
- Set of pliers or multi-grips
- Suitable container for catching coolant
- Universal Gear puller (not ‘claw’ type)
- A White Marker Pen (or liquid paper) and small mirror is handy for confirming timing marks.
- Degreaser, rags, etc.
The vehicle we are using for this article is a 2000 Hilux 4wd fitted with a 5L (3 litre) diesel engine that came to us with a leaking waterpump. Without even pressure testing the cooling system it is usually obvious when one of these waterpumps calls it a day. After removing the bash plate (if fitted) the leak will usually become evident fairly quickly in the centre of the car towards the front of the engine.
Underneath the car looking up towards the timing belt cover will give you an even better diagnosis of the leaking water pump.
Our first step is to remove the radiator cap and loosen the radiator drain plug and release what coolant is left in the radiator, preferably with a container underneath to catch it and not where you will be doing the job! Be gentle with the drain plug as they are plastic and can become brittle over time. Once the coolant has stopped flowing re-tighten the drain plug finger tight only.
To make life easier I remove the negative terminal off the battery and then remove the positive lead that goes across the top of the radiator to the starter motor. The factory setup has a 12mm nut that can be taken off to separate the lead from the terminal and there are two plastic clips on the radiator shroud that hold the lead. Once these are undone you can move the lead over to the passengers side of the engine bay and out of the way.
If your car is A/C equipped you can now also remove the 10mm bolt that secures the hose to the thermostat housing bracket so the hose can be moved up a tad when it’s time to take the timing cover off. Next item to remove is the radiator overflow hose from the radiator neck. Be gentle here also as the plastic radiator tanks become brittle over time.
Next on the list is the top radiator hose.
Removing the fan shroud is the next step. On the later model Toyota’s the shroud is plastic and has a removable bottom section, on some of the older ones they are metal and unbolt in half – top and bottom, and on some early 80’s Toyota’s they are metal but in one piece which requires removing the nuts for the fan and bolts for the shroud and removing it all at once. Make sense? Didn’t think so!
Anyway, the shroud we are dealing with here has a removable lower section to make life a bit easier. There is a clip either side, about half way down that can be levered out to release the bottom piece.
With a bit of maneuvering the small bottom section of the shroud should come out easily enough. Next we move on to the four 10mm bolts holding the rest of the shroud in place. Two each side and the bottom one on the passengers side can take a bit of getting to but it’s not too bad.
Now with the shroud out of the way we can concentrate on removing the four 12mm nuts that hold the fan on. Once the nuts are removed it may take a bit of ‘backwards and forwards’ moving of the fan blades to loosen the fan hub from the waterpump shaft.
The next step is to start removing the fanbelts/drivebelts. The first one is the Power Steering belt which is removed by loosening the 14mm nut on the end of the power steer pump mounting bolt, best got at from underneath the car. The pump is on the passengers side of the engine.
Next we need to loosen the 14mm upper ‘adjustment’ bolt of the Power Steer pump. Just a couple of turns is usually enough to be able to push the pump towards the engine and remove the belt.
Next up is the Air Conditioning belt which is removed by loosening the 14mm nut on the ‘face’ of the tensioner pulley (1) and then winding the 14mm bolt (2) anti-clockwise until the tensioner pulley can slide towards the engine enough to remove the belt.
The alternator/fan belts are next in line and you really have two choices here – you can either remove the waterpump belt pulley with the belts or loosen off the alternator adjustment and remove the belts that way. I prefer to do the former as once you have everything apart it is a lot easier to loosen the alternator mounting bolts.
Removing the alternator/fan belts and pulley in one
Our next step is to remove the heater hoses and piping that runs across the front of the engine. Apart from the four hose ends there is also a 12mm bolt on the thermostat housing that has to come out.
Then we are left with two vacuum pipes that run across the front of the timing cover. Putting a mark on the hoses so they go back in the right place is a good idea (duh!) and once you have removed the hoses from the pipes you can then undo the two 10mm nuts that hold them to the timing cover, the 12mm bolt into the thermostat housing and the two 10mm bolts that hold it all to the air intake.
The next step is to remove the balancer. You have two choices for removing the balancer bolt. The first solution is to completely remove the radiator and use an impact gun to loosen the 19mm bolt. The other option is to temporarily refit the negative battery terminal and positive lead to the starter motor and using a 19mm socket and breaker bar. What you do is wedge the end of the breaker bar against the passengers side chassis rail and momentarily operate the starter motor with the key.
Because there are a number of pipes running down the topside of the passengers side chassis rail on these vehicles I recommend using a couple of strategically placed blocks of hardwood to avoid damaging the power steer lines. Also be sure that there is nobody around that could get hurt if the breaker bar decides to let go while your doing this. I have used this method on countless occasions without any problems, just be safety conscious.
Once the bolt is loose you can continue to undo it with a ratchet and 19mm socket and don’t forget to remove the negative battery terminal first and then the starter positive lead again as it will get in the way.
Once the main balancer bolt is removed I find the easiest way to remove the balancer is to remove the two outer rings (A/C and P/S belt pulleys – 6 x 12mm bolts) which gives more room to fit the balancer puller.
With the balancer removed we can now start to remove the timing cover. If your car is equipped with air conditioning you will notice that there is an idler wheel on a bracket at the top left of the timing cover. This idler is removable by removing the 14mm nut holding it from the back. Once this is removed there is enough room to get the cover out even though it doesn’t look like it! You can go to the trouble of removing the bolts securing the A/C compressor and this bracket if you want to but believe me it adds a lot more work to the job.
The only real issue that you will face by leaving this bracket in place is removing the timing cover 10mm bolt that is almost directly behind the bracket but with some patience and a 10mm spanner this bolt shouldn’t cause too many dramas for you.
Next item on the agenda is to remove all the 10mm bolts securing the timing cover, including the three around the waterpump area. Once all the bolts are removed it’s time to wrestle (err.. manoeuvre) the timing cover out. It does take a bit of doing but believe me it can be done without the need for a tube or two of Araldite afterwards!
Now that the cover is off it is time to evaluate the situation.
As you can see there is quite a bit of engine oil floating around the place which tells us that either the camshaft seal and/or the tappet cover gasket has been leaking. Either way the timing belt will be getting replaced because of oil contamination even though it has only travelled around 50,000km. The waterpump is buggered for sure and more than likely the crankshaft seal will be leaking also.
Before going any further, if you have decided to replace the camshaft seal (a good idea even if things are relatively dry) we need to loosen the camshaft sprocket bolt. Once again out trusty breaker bar and 19mm socket will come in handy for this.
One sharp blow on the end of the breaker bar should be enough to loosen the bolt or if you have an impact gun it should be no hassle. Just loosening the bolt is all that is needed at this stage, we still have the timing belt fitted and still need to line up the timing marks.
Speaking of aligning timing marks, now we can refit the crankshaft balancer bolt into the crankshaft thread and use this to rotate the engine in a clockwise direction to line the marks up. We have three marks to line up with these engines – the camshaft, the injector pump and the crankshaft.
Although the photos don’t show it too well there is a notch or line in the cam gear that has to line up with the arrow on the rear timing cover which is located just above the waterpump at around the 6 o’clock position.
The injector pump also has a notch or a line in the gear that must line up with the mark on the engine. Don’t worry about the stripe of yellow paint, that’s just there to confuse us!
The crankshaft marks are not the easiest to spot but there is a small cutout in the crankshaft gear that has to line up with the mark on the oil pump housing. Pretty basic stuff, the only thing that can throw a spanner in the works is if you have the crankshaft marks lined up and the camshaft and injector marks are 180 degrees out. One full revolution (clockwise only) of the crankshaft should bring things into line.
Once you are confident that the timing marks are lined up correctly it is time to release the timing belt tensioner. By loosening the 14mm tensioner bolt (red arrow below) you will be able to push the tensioner across towards the drivers side of the car and then re-tighten the bolt to keep the tensioner in the ‘released’ position. In the photo below you will see that I am using a lever bar to move the tensioner – DO NOT do this if you are planning on re-using the timing belt as it may damage the belt. The tensioner does have a spring on it but hand pressure should be enough to move it across if the belt is to be re-used.
Also on that note, if the belt is to be re-used mark the belt so that you can be sure it will be rotating in the same direction once refitted. The teeth on the belt ‘wear-in’ to travelling in one direction and changing the direction can cause premature belt failure. Not that I recommend you reuse any timing belt, even if you have to pay $100 for a new one it is cheap insurance against possible engine damage down the track.
If you are replacing the tensioner unit, another good idea while you’re at it, completely remove the adjuster bolt and the attaching bolt. (Pictured below)
Ok, time for the belt to come off and you will more than likely notice that the injector pump pulley moves around an inch or so as the belt comes off. Don’t stress, this is normal and we can leave it there until we come to refit the belt.
The next step is to place a suitable container underneath the car to catch the remaining coolant and remove the six 12mm bolts securing the waterpump to the block. The bottom right-hand bolt also holds a small bracket that the timing belt tensioner spring attaches to so be aware that you will have to remove the spring as this bolt comes out. Once all the bolts are removed a gentle tap on the top of the water pump should be all that is needed to dislodge it.
Next up we can turn our attention to replace the camshaft seal by removing the four 12mm bolts securing the rear timing cover to the cylinder head. Once removed we can CAREFULLY prize the top of the seal out and remove it. Be careful here not to mark the camshaft surface as you may end up with a worse oil leak than you had in the first place!
To fit the new seal use a socket that has the same outside diameter as the new seal and gently (and squarely) knock it into place. These cylinder heads have a ‘step’ where the seal bottoms out and can’t go in any further. Not all seal arrangements are the same so it pays to take note of how far in the old seal sits before removing it. A good clean-up and degrease of the surrounding area and rear timing cover and we can refit the cover and move on to the crankshaft seal.
There is a thin tin ‘disc’ that sits in front of the crank gear and this is removed by lining up the ‘groove’ in it with the keyway. Once this is removed the crank gear needs to be removed with a puller. Don’t be tempted to lever the back of the gear to remove it as this will only crack the gear, they usually take a fair bit of moving! Once the gear is off we can replace the seal in the same way as doing the cam seal, refit the gear by gently knocking it back on and refit the ‘disc’.
I am going to have to leave this article here as I found a nice little crack in the cam gear of this engine and being a Sunday we have no way of tracking down a replacement. Part Two is finally finished and can be found HERE.
‘The Boss’ checking my work!