Amazon: Water Pump: Gap Against Head

[gothamus]

B20e / SU HS6 / '64 Amazon-

I swapped my water pump and found from first running it was not secured correctly and leaked. The way it leaked was either the seals to the head or the gasket toward the top.
Round 2 - before I fill her up, my insecurity here- Should expect that gap where the top of the wapu comes against the head? Where the sealing rings are pressed against the head. I tried to measure what I see which is just over 1.066 mm, give a bit maybe. Cool?

I read and watched good instructional material. New gasket and silicon sealant often suggested. Silicon grease on top of rings. Bolt lower left. Pressing up from the right side- the upper right bolt secured. Used a bar to maintain pressure. Gave the upper left some pressure up and secured upper left bolt. Then the remaining bolts and hardware, pipes.

But, is it enough, I ask myself? I could put greater pressure on the pump. I put enough to feel a stopping point. I can see the rings from front and with mirror around and I can't see deformation of seals. But there is a noticeable gap, right? Normal? I think there was 18 months ago when I did it before. Doubts though! That's a lot of work to do again!

[Ron Kwas]

G;

The gap you notice is equal to the thickness of Head Gasket...since HG does not extend to over WaPu, the rubber Sealing Rings in two heights are (should be) included with WaPu to do this sealing and they are proud of the WaPu housing (top of which is flush with top of engine block) to do this...but...thing to watch for...if a tall HG is in place, and the short Sealing rings are installed, OR if Sealing Rings are moved askew (easy to do!) while rotating the WaPu into place during installation, leakage will result...it's tricky to keep both Block Gasket and Sealing Rings in proper place during installation...work carefully!

Good Hunting!

[142 Guy]

B20E - do you have a correct B20E head gasket or do you have a B20F head gasket? If you have purchased a fuel injected top end gasket set from Elring in the last 6+ years, it will come with the thicker B20F head gasket. The appropriate gasket for use with a B20E if you want to retain the original compression ration and the all important quench band is the 0.028" (compressed height) B20B head gasket.

Head Gasket thickness gets back to Ron's comments about the two lengths of sealing rings. You need to know what head gasket you have. If you measured the 1.06 mm correctly, that is 0.042 " which seems more like a B20F head gasket so the slightly longer rings would be appropriate. However, I recently did some work on my car and the OEM water pump gasket set came with long seal rings that were way too long. However, I have a B20B head gasket on my B20E so the shortest rings worked fine - so far.

The way it leaked was either the seals to the head or the gasket toward the top.

Are you talking about the top of the gasket between the pump and the block? If so, I don't like to use silicone sealants anywhere on the engine. I do like to use Hylomar Universal Blue. It is a non setting sealant that is durable and easy to use and has excellent performance. I apply Hylomar to the pump housing and let it dry then apply the gasket. I then apply Hylomar to the interface between the gasket and the block and let it dry before mounting the pump to the block. The hylomar will keep the gasket in place while doing the install.

To tell the truth, I lie about using Hylomar. I now use Permatex Permashield because it is 1/2 the price of the Hylomar and easier to get; but, it is effectively the same product.

https://www.permatex.com/products/ga...lange-sealant/

If the Permashield is not available on your side of the Atlantic, Hylomar is the treat!

[c1800]

I had a similar issue when installing a new WP on my 1800E. The “genuine” Volvo WP was advertised as including the taller seals. They weren’t the taller seals. (also the pump was advertised as Made in Italy, it wasn’t, was made in China). I had to acquire those taller seals separately. So it appears that my 1800E has a thicker head gasket, based on comments.

In any event if you have a gap, then you’ll need the taller seals, and yes some silicone grease is helpful, with due care and attention to seal alignment, and upward pressure.

Make sure the surface on the front of the block is clean and smooth. I used a 3M disc to clean and polish. I found no need for sealant , just a smear of grease to hold the gasket in place while manouvering the pump upwards.

[Derek UK]

New seals should be the same as the ones that came out. The difference between the 2 sizes is obvious. Stick the gasket to the block with a bit of grease and add a little on the WP side of that gasket. Fit pump carefully. making sure the seals aren't skewed. Just put the bolts in hand tight. Use a length of wood between the underside of the pump and a trolley jack under the front of the car. Pump up the jack so it just starts to lift the engine. The pump should slide up the greasy gasket and allow the seals to seat against the CLEAN head. Tighten bolts. lower jack and remove the wood. Fit belt or whatever you are going to do next.

If the leak at the moment is round the seals you can try the jack method after loosening the bolts. If the seals aren't skewed it should fix the leak. But, I would start from scratch so you know what is going on.

[gothamus]

Excellent replies from all which speak to my concerns and considerations.

I thought about the head gasket but I didn’t reflect on it in regard to this spacing. I should think I have the correct B20e, but it’s been a year and a half and I’m not sure right now. I’ll scare up the receipt. I bought a B20e gasket for spare last month. I better verify the match in case I use it. And make another attempt at measurement on the current spacing.

The sealing rings are the taller sort, which matched what initially came out at engine rebuild. Now it’s pointed out about the thickness in relationship to that gap I’ve looked again and the Wapu is flush with the top of the block. I’ve looked for distortion at seals. Good only so far as one can see.

My Wapu was made in Germany. I’m not mucking about with discounted manufacturing for German made prices. Several layers of no-trust.

I wrote wrongly about my sealant earlier. ( didn’t have the product on me when I wrote, silicon was on my mind I guess). I learned about the Hylomar in last minute readings which didn’t leave me time for Amazon delivery. I found that Permatex which says ‘similar to’ on the box. Same product posted above. My gasket is a bit of a downgrade from the aftermarket that came with the water pump since that was ruined on removal. I have a gasket kit on the shelf and it had the right one that is made of original type of material. Better than construction paper, I am sure, but feels like it for a description. I think the sealant upgrades the paper though.

I did a carefully non-abrasive cleaning of the head section. Rubber taser blade along with some good off on a cloth, careful that there wasn’t so much to drip to the timing cover case. I have a very old and flat, smooth stone for grinds. This for smoothing a machined surface. When oiled lightly, it does a good job for cleaning. There should still be a fine texture but no lumps of foreign matter.


I’m done with my work day now and heading to the car for final burping. I had time last night to fill up and burp. But not time to run longer or drive. But no drips so far.

Two months of doing projects. This job is where it started. Back in June I had installed a new pump and new rad. Had to move the car around the block which is a far as I got. As I backed into the parking spot I couldn’t use the clutch to change gear out of reverse. Curses! I grumbled. Not even around an entire block and a new problem! But wait, that was good. Covid meant parking rules suspended. I can work without moving the car for a long time! Now I’m done with five renewal projects and I must check them all. It had left my mind that I hadn’t truly validated the water pump job.