zaphod

Silly question, but I'll ask it, having read the procedure for replacing the water pump, it is allied with changing a timing belt - a job of 10-14 hours. What actually needs to be removed to change the water pump, please? Is there a tutorial available just for this?

Yes, you guessed it - after my other posts, the water pump not pulley, I've concluded, is making a hell of a racket, and yes there is a suggestion - although I have not confirmed - of a leak from around here, this morning.

Thanks

3UZFTE

I'm not really sure what your asking, but the water pump does not take 10-14 hours. 4-5 maybe for an experienced tech with the right tools. The timing belt does not need to be removed, but there is a belt tensioner that will not allow you to remove the belt from the pulley to access the pump. You need to unbolt the tensioner, and loosen the belt, and since your there, the belt is a lot cheaper than the waterpump, and you might as well replace the pulleys too. The theory is why spend the time to dig that deep into the motor, and not replace the cheaper things in there? If this doesn't make sense, don't attempt it. Do yourself a favor and do some more research as there is a quite awesome search function in CL.

CrashGT007

http://www.lexls.com/tutorials/engine/timingbelt.html

Will tell and show alot.

zaphod

Thanks 3UZFTE. Yes, I have dipped into the tutorials and search function and it is great, so many thanks to the contributors. Indispensable stuff.
The timing belt was changed last year by the previous owner, who is a good friend of mine, hence my query. I am more used to working with Saabs, see my signature for the current fleet, and this Lexus is the first I have owned - and highly chuffed, too, I have been with it, for the past 10 months or so.

I am no expert mechanic, but no novice either, and will give anything a go within my capabilities, and with the instructions, and the beneifit of other's tips and experiences - so, thanks again!

LexLS

Not really sure how you can get the water pump off without removing the timing belt

http://www.lexls.com/tutorials/engine/timingbelt.html

python

iTrader: (4)

lexls is exactly right, the waterpump is behind the timing belt

3UZFTE

The belt doesn't need to be removed from the engine, it just makes it more difficult to access no doubt, but trust me, it's been done. Once the tensioner is removed, there is enough slack in the belt to remove them from the idler and tensioner pulley, and that is all that is need to be removed to access the belt. My thinking is why do a 5 hour job, and not take 30 seconds to remove the belt?

rx7guy

I also recommend a flat or offset box wrench with the ratcheting feature as there are two bolts on the side of the A/C compressor(I think) that needs to come off and it's such a tight space that you can't even get a socket in there unless it's super shallow.

Doing it manually is horrendous.

rx7guy

If you decide to do the timing belt while you're in there, I recommend this link as I had to go through it and the pictures that were provided along with mine helped a great deal.

Good luck.

https://www.clublexus.com/forums/ls4...-question.html

rx7guy

FYI, I took a look at the water pump and there was no way to remove it without removing the timing belt cover; which means you have to remove the crank shaft bolt.

The bottom water pump bolts cannot be removed without removing the timing belt cover. Maybe you can pry the cover to get to the bolts but I would think it would be very hard or you might break the cover to do it.

I also took way longer than I wanted because I had to buy another compressor to remove that darn crank shaft bolt(had to torch several times to loosen the bolt up).

Anyways, this was on a '93 LS 400 for your information.

It can be done in 4-5 hours if you're experienced and you have everything you need to do the job but if you're a novice like me and don't have everything it definitely will take longer.

Good luck.

zaphod

The reason why I am fighting shy of removing the timing belt, is because that will mean realigning everything, won't it? If I make a mistake - then......

I'll have a preliminary look around tomorrow, get the radiator out, check hoses for something really silly or embarrassing, do a reverse flush, then replace. Pulley will be replaced during the week - been unable to secure, quickly

rx7guy

I believe 90-94 were non-interference engines which means if your timing belt snapped all it would do is shut down your car, nothing catastrophic.

The pictures provided above should help with the re-alignment immensely. You might as well do everything if you're going through the trouble of getting there. It's a bit more work but at least you won't have to touch it again for at least another 90K miles.

3UZFTE

x2, and Zaphod, if you take everything apart correctly, lining the engine up is a walk in the park. If you buy an OEM belt, it has the marks indicated on the belt so it is ALMOST impossible to screw up.... ALMOST.... IF you crank the engine over to TDC, everything will line up how it should, even if you don't everything will line up, you just won't have any point of reference if you are a tooth off. Simple, simple, simple... just read and read and read how to do a timing belt until you feel sick and comfortable tearing into it. If you have any problems, that's what were here for.

zaphod

Many thanks for your help and experience everyone - it is truly appreciated - and I don't bulk or hesitate at asking what may seem to be stupid questions - we all have to learn and start somewhere!

My background is in Saabs - there were four in the fleet at one time, which can get far more complicated! Preliminary take apart and inspection today, and if I get the chance, photos, and report to boot. I like to give to forums as well as learn and receive, and have done this to the past, regarding procedures. The ones I have read here are simply great, so, kudos!

I have much to learn about Lexus's..........

zaphod

Right, just back in.

It was an afternoon of nipping in and out of the showers, I'm afraid, so few piccys. But preliminary investigations completed, and some detailing along the way.

Battery and tray out - for a clean.

Radiator removed, accumulation of leaves and debris, including a dog end cleaned out from it and the tray, two main hoses off for inspection and clean up. No sign of splits, leaks or delamination from radiator and hoses.

Gave the radiator a good reverse flush - fluid clean and no debris.

Pleased to see the ATF that oosed was the correct pinkish colour.

All put back together.

Then replenish the coolant, both bleed plugs undone but in situ - pure water at the moment - I'll be replacing with a 50/50 antifreeze mixture in due course - filling the level of the expansion tank as it dropped, and reving to around 2,000 - 2,500 rpm for a minute, keeping an eye, for bubbles, until opertaing temperature was reached.

Noted that the water pump, or is it the top pulley - I initially thought it was, doing a screwdriver listen check - was making a lot of noise, during this process until I replenished with water to it, directly through the bleed by the thremostat.

Is this water pump in its death throws, or an indication of bhg?