Can't remove water pump pulley- AHU Mk2 swap

worm12ga · April 2nd, 2012, 10:40

I'm hoping for some old mechanics tips or something here.

As background, I'm running an AHU from a 98 Jetta currently installed in a 91 Jetta. As part of making everything fit, I did an AC delete, and am using a pulley to run the water pump off the serpentine belt, instead of the v-belt.

I'm trying to remove the water pump pulley so I can remove the lower timing belt cover, since the cover does not clear this recessed pulley the way it would clear the original pulley, due to the different offset. I need to get the cover off to check on the crank sprocket, as I suspect it has begun to slip.

I saw in some of the writeups that you can counterhold the pulley with a wrench behind it...but that is the stock pulley. The offset on this pulley does not allow a wrench to fit behind it.

I've tried vice grips, an impact driver, penetrating oils, various combinations of wrenches, but whatever I do the pulley just wants to turn, and I can't get any leverage against the bolts. I've tried with both the belt off and the belt on, but even with the belt on it just slides on the belt. I'm getting close to wrapping a chain wrench around the pulley, but I know this will really scrape up the surface.

If anyone has been in a similar situation, PLEASE let me know how you overcame this problem. I'm afraid to drive the car until I diagnose the crankshaft problem, so I'm stuck driving a beater pickup in the meantime (crappy MPGs)

Baron VonZeppelin · April 2nd, 2012, 14:22

If you still have the allen head bolts in use -
get 2 allen wrenches/bits the correct size -
use 1 to hold for leverage on 1 bolt -
then use the other to break a bolt loose -
then do another bolt -
keep going until all 3 have had the intial torque broken loose.

Then you should be able to get the last 1 loose again (that retightened as it was used for leverage) without much problem.

If ALL else fails - drain coolant and remove entire water pump housing assy from the engine.

scottp · April 5th, 2012, 18:30

I just had this problem today. using one allen key to counter hold while loosening the second will not work. What I did is used a pipe wrench from behind. My pump was unbolted (loose) so I could wiggle it around. It sucked. I just wanted to kill myself. Good Luck!

rdkern · April 5th, 2012, 19:26

How about a slightly-too-large hex? Tap a tad, 3/8 socket. Could be cheap enough for a 1-time use. It should work.

Baron VonZeppelin · April 5th, 2012, 20:22

Quote:

Originally Posted by scottp

I just had this problem today. using one allen key to counter hold while loosening the second will not work.

Has worked for me many many times (everytime) on water pump pullies.
Individual methods and situations could alter others results.
Glad yours came off eventually.
Hope worm12ga got his off too.

worm12ga · April 6th, 2012, 00:57

Haven't had time to work on it. I need to cut down one of my long hex sockets so I can try Baron's suggestion, as I have only one set of short metric bits, and the long bits don't allow a good angle/access. It's been a long time since I was under a mk3 hood, but I'm guessing there is a little bit more room to get at the pulley than a mk2.

ScottP- I would love to get a pipe wrench in there, but with this recessed pulley there is even less room behind the pulley than on the stock setup.

rdkern- I don't think you understand my problem. A different size hex bit would be just as bad if not worse. My problem is lacking a way to hold the pulley still so it doesn't turn while I break the bolts loose.

If Baron's trick doesn't work, I borrowed a rather large chain wrench with a 2 foot handle, might put a piece of inner tube on to protect the pulley surface. This thing is coming off one way or another, I just hope I don't destroy the pulley in the process.

schultp · April 6th, 2012, 05:25

Could you use a strap wrench around the pulley? Here is a pic of a set from Harbor Freight for $4.99. I have also used an old serpentine belt section and a pair of vice grip pliers to make my own strap wrench.

Abacus · April 6th, 2012, 05:48

Just take a piece of rope and twist it around the pulley, then keep twisting until it's tight. If it slips, twist some more. That'll lock the pulley so it won't move and you can unbolt it.

worm12ga · April 6th, 2012, 07:12

I thought about the strap wrench, but I thought it might just slip, same as a piece of serp belt. I could be wrong. I'm gonna try counterholding with the other bolts as suggested earlier, as soon as I get home from work today (been away all week).

Abacus, that is a good suggestion, but this is a smooth serpentine belt pulley, I think the rope would just slide off when you tried twisting it. A rope would probably work great on the v-belt pulley that's 'supposed' to be on there.

Then once this pulley is off, I get to make a tool to pull the crank sprocket. Sometimes I think VW engineers design things to require special tools just to torture us.

schultp · April 6th, 2012, 18:00

Quote:

Originally Posted by worm12ga

I thought about the strap wrench, but I thought it might just slip, same as a piece of serp belt.

They don't slip. You orient the handle (or vice grips if you do the homemade version) so that as you torque the bolt the handle grips and tightens the strap (or serpentine belt). I have done this several times. If you have the orientation backwards you will quickly realize since it will slip. I always keep a broken or old serp belt around for this use.

Or Turbo Diesel · April 13th, 2012, 00:07

Many times the cheap, soft allen bolts start to have problems. Real stubborn ones get gently heated up with a propane torch, then use the allen wrench on it, vice grip the outer portion so that won't expand, use another allen to help lock it, and go at it. The heat is the key to break the mechanical seal. If the bolts get screwed up, just go buy some new stainless ones and don't look back. In fact you can get allens bolts for the crank too.

Do be careful, keep some water around, and wear eye protection!

I learned the heat trick from my ASE mechanic friend. Good luck.

worm12ga · April 14th, 2012, 08:34

Or Turbo Diesel, while the oem allen bolts may be inexpensive, they are not what I'd call soft. I'm not sure what the rating of the original bolts is, but I'm sure they are a good bit harder than most stainless bolts you can buy locally. I love using stainless on any non-critical applications, like the body, interior, exhaust, etc but not on engine parts. I would stick with carbon steel bolts on the various pulleys. Does anyone know what the original VW fasteners are rated to?

The torch idea, however, is a decent suggestion.

worm12ga · April 24th, 2012, 16:03

Well I finally got around to dealing with the car today. Had to grind the heads off of two out of three bolts to get the pulley off. Was then able to remove the studs with pliers.

Got my crank sprocket off too. The thing was murdered, I'm so glad I didn't destroy the engine. Now I just have to decide what to do to the crank before I install the new sprocket.

Thank you everybody for your suggestions.