Water Pump leaks WORSE now!

[shifty]

In March of 2004, I replaced the timing belt, tensioner, water pump, coolant hoses, vacuum hoses, all intake and exhaust gaskets, a lot of hardware for the parts I replaced, and flushed the radiator.

Some of you may remember the problem I was having with the water pump at the time. I've never done a 535i pump, so I don't know what's involved with replacing it, but I can tell you the 528e pump is a BITCH to install.

You have to align the impeller with the opening for it to slide in, but you first have to slide the right side of the pump under the timing belt tensioner. You also have to have the pump rotated a little bit counter-clockwise at first so that you can fit the tensioning pin and spring in between the pump and the tensioner. Then, you have to rotate the pump clockwise, making sure the pin and spring stays in place.

Sound hard? It sure is, but I didn't even mention how you have to keep the gasket lined up and not kinked, along with all of that stuff!

Last year, I just decided to use some RTV sealant and call it good. The instructions in the Bosch water pump I bought even said to use that as the gasket. Apparantly, I either didn't apply it well enough or I didn't let it cure long enough (I guess 24 hours is too short of a time), because it started leaking about 8 or 9 months later.

Yesterday, I finally had time to remove the water pump clean up all of the RTV, and replace the gasket. I vowed to use a new gasket and NOT use sealant.

It took me about 45 minutes to get the coolant drained, radiator out, applicable hoses off, fan and clutch off, cap and distruibutor out, and finally the water pump out. Another 20 or 30 minutes later, I had finished cleaning up the RTV from the water pump itself and the mating surface on the front of the block.

It then took me close to an hour -- about 2 hours LESS time than last time! -- to get the water pump and gasket and spring and pin and impeller lined up properly to get the first bolt in. By the way, I used new bolts and washers for the water pump, this time.

The gasket appeared to be lined up properly for the second and third bolts, but now that I think back on it, the bolts were harder to thread in. I'm afraid I may have knicked or kinked the gasket because it wasn't perfectly installed.

I replaced all of the other parts I was going to replace and got everything buttoned up. When I filled it with coolant. . . yup. . . major leakage. The leak was hardly noticeable before, but this leak is quite obvious. I wouldn't be able to make it down the street back to the dorm without losing almost all of the coolant.

So, the car is parked at the garage for today and tomorrow -- they're not open on Sunday and Monday -- and I'll go back and put a few hours of work into it on Tuesday before I have to go to work. At this rate, I may be ready to drive the car by next weekend!

Does anyone have any ideas on HOW I can be sure to get this gasket in properly. Do any of you eta owners have some kind of secret or a specific procedure for installing your water pump and gasket properly? How many people use RTV as their sealant and don't use a gasket at all? How many use RTV to hold the gasket on the pump properly for installation?

How many just take it to a mechanic and call it good?

TIA,

[fastpat]

I just did that with my 325i when I was replacing the timing belt and the rest, now let me see if I recall just what I did.

I glued the WP gasket to the pump itself with Hi-Temp RTV, the red Permatex stuff. That does four things; gives you a slighly thicker gasket, a somewhat more compliant gasket, holds the gasket in place, and one that will more likely come off with the pump when you replace it in the future. You can also coat the side of the gasket that goes against the engine with a very thin coating of Permatex Anti-seize to aid in it's removal in the future. The RTV is laid down in a VERY thin coating prior to installing the WP gasket because you don't want much squeeze-out of the RTV.

My result has been good, no leaks from the WP.

[shifty]

Pat,

The RTV sealant I used last time was orange, and that was the only gasket I used. As I recall, it had about a 24-hour cure time.

When you say you glued the gasket to the pump with the RTV, do you mean you just let the RTV cure before installing the pump? If so, that should be no problem for me since I can only work on my car one hour a day this week. So, I should get the pump off the car Tuesday, and I can install it on Wednesday.

Thanks for the help. I was kind of thinking of using some RTV to attach the gasket to the pump anyway, but I hadn't thought about letting it cure before installing it. Very good idea.

[a]

Ive done 3 eta pumps so far. The last 1 about 3yrs ago. I think I used the old school permatex non- hardening gasket goop. You brush it on and let it "skin" over. about 20 minutes. Then you put the gasket on to the pump. An old shadetree trick is to tie the gasket on with loops of thread on each bolt hole. I used blue rtv as a waterpump gasket on my last Jeep. Yrs later , i was still picking squeezage out of the radiator.

[shifty]

[QUOTE="a"]An old shadetree trick is to tie the gasket on with loops of thread on each bolt hole.[/QUOTE]

Andy,

OUTSTANDING idea! What I might end up doing is attaching the gasket to the pump with some RTV and then tying the holes up like you mentioned just to be completely sure it stays on there.

Thanks!

[Steve Haygood]

uhhhhhhhhhhhhhhhhh one word ......BOSCH ........get a real water pump

[shifty]

[QUOTE="Steve Haygood"]uhhhhhhhhhhhhhhhhh one word ......BOSCH ........get a real water pump [/QUOTE]

Steve-o,

Don't you remember you ragging me the other day about paying $55 for a water pump? It was in the thread about which is the best water pump brand. What you must have missed is that my Pep Boys water pump WAS a Bosch water pump!

BTW, I replied in that thread and mentioned that my service records say I paid $45 for the pump. I'll come to you next time, but at the time I had to get the pump ASAP.

[fastpat]

I let the thin coat of RTV skin over for about 20-30 minutes before attaching the gasket to it. It's still slightly tacky and holds the gasket quite well. No need of other methods of holding the gasket. Further, the reason you use a very thin coat of RTV is to avoid squeeze-out that goes places where you don't want it. When I say thin, I mean a playing card is thick by comparison. Of course, you don't have to use RTV, you can use just the gasket and hold it in place with just a bit of grease strategically placed on the rim of the pump to tack it down. Not as reliable as the RTV method, though.

My water pump was a BMW pump, had to go that way because I ran out of time to order a lower cost alternative. :p

[DGM Calgary]

Brad, I've been thinking about this and I can't get away from the amount of leakage - " I wouldn't be able to make it down the street back to the dorm without losing almost all of the coolant."

It just doesn't sound like a gasket leak to me (seep or drip).

Are the bolts bottoming out? Is it the right pump (I've never had a problem with the impeller "...lining up on my M20's")?

Part numbers be damned - I've had lot's of improper order fills with proper part numbers. Measure the bolts and compare the pumps just for a laugh.

[Techboy]

Shifty this is a very easy leak to create and is even done sometimes by dealer techs in too much of a hurry. The product you want is from Permatex and it is called Hi Tack (or is it High Tack?) in a blue aerosol can. It is a spray on gasket adhesive and is the bomb for what you are doing. Next, get a new WP gasket of good quality. When you disassemble, before removing the waterpump, push the pin back into the timing belt tensioner and lock a small set of visegrips onto the side thru the tensioner so that it is and stays out of your way (BMW has a special tool for this as they do for everything). After removing the pump, clean everything up and look very carefully at the gasket/pump orientation, there is only one correct fit but at least one close fit (which you don't want). After determining the correct gasket orientation, Hi-Tack the gasket to the pump and let dry for a few mins. Install the pump (at this point i put a couple bolts in the pump before installing to make doubly sure that the gasket remains correctly aligned), the installation will be a LOT easier now that you dont have to deal with the spring and pin. Tighten the 3 pump bolts, release your visegrips and make sure the pin locates well in its socket in the pump. Connect hoses, leak test and button it up!

[shifty]

DGM,

It is absolutely, without a doubt, the correct part. I compared it to my old one last year. It's a Bosch brand water pump for an '87 BMW 528e that I got from Pep Boys.

The bolts and washers are brand new from DPP.

The impeller not lining up: it does line up, but it's hard to slide the right side ear that holds one of the bolt holes behind the tensioner while getting the tensioner spring/pin into place AND holding the gasket.

The bolt/washer comment reminds me:

Are all three bolts the same, or is one of them a little longer than the other two? I removed one longer bolt from the car, but the three I bought from DPP are the exact same part. Perhaps this is a problem, or are all three bolts the same?

EDIT: Techboy, I just caught your post after sending this one. Great info! I especially like the tensioner spring/pin idea.

[Edit by Shifty on [TIME]1110216227[/TIME]]