How stop these fittings from leaking

[hd002e]

The water pump">raw water pump fittings on my Volvo MD2002 are a nightmare. The bronze pipes are barely held in place by thin seals and there is not much keeping them in place. So they leak. Badly.

I went through the same with my heat exchanger and accepted the fact that these types of fittings will always leak, it has been leaking all over the engine and I keep diapers under the engine and toss them out regularly.

At the raw water pump location though, I cannot afford a leak because its right next to the battery.

I am at my wits end, I am open to all suggestions on how to stop this leak.

Thank you!

[belizesailor]

Maybe change out the fittings. Shorten the pipes, braze on a piece to the tubes the same diameter as the pump fittings and install a section of hose.

By their nature, you will get leaks sometimes with a raw water pump, but this should provide a more positive seal.

[Pete7]

Are you using new seals? we have a packet on board but they have gone hard so need replacing really. However, we don't have any leaks.

What is the thin wire clip for?

Pete

[tkeithlu]

Wow! You've done your best to seal that sucker. Evidently, the gasket and sealant isn't enough to make up for what ever curvature/flexibility there is in the plate. Assuming the others are similar:
1. Flatten the inside surfaces of the plates. Staple 1000 grit automotive paper on a smooth board, and hone the plate by dragging it down the paper.

2. Check that the pump face is flat. Clean it and put the flat plate against it.

3. Use washers when you tighten the screws to distribute the load and keep everything flat.

4. Use a thicker gasket. Get some automotive (same trip to auto parts store) gasket paper, and cut new gaskets. Ask us if you don't know how to do that.

If you must use goo, use thin layers on all four mating surfaces, screw in place but wait 24 hours before tightening the screws.

[tkeithlu]

Oops. It's the pipe fittings, not the cover plate.

1. Disassemble.

2. Inspect the threads (?) holding the tubes into the pump.

3. You may need to replace the tubes, or if you have some slack, extend the threads so you get a longer grip. See Belize Sailor above.

4. If it's ot held by threads, just what holds it. We can start over with a picture of the offending tube loose from the pump.

5. Hang in there. It's frustrating, but fortunately there are only so many ways it can fail, and you are going to find it.


Third look. Are these tubes ended with O-rings and then held in place with that little clip? No wonder it fails. Replace the seals, and for a quick maybe cure, bend the clips so they are tighter. Then it's replace the clip.

[Pete7]

These seals can best be described as a square profile o ring held in place with lots of faith.

Pete

[tkeithlu]

Volvo did that? I used to really respect them, until I started hearing stories on this forum. At least Detroit Diesel (I own a semi-antique 4-53) had the common courtesy to use threads, nipples, and hose clamps.

[jamhass]

I fought these things for years on my 2003T. There are a few things to check:
1. Are the seats the rings sit in good and clean, including making sure old rings are not stuck there.
2. Are the pipes themselves in good condition? Some, especially the ones on the tranny do corrode, leading to leaks.
3. Don't force the installation. Often, you must loosen a few parts to allow the pipes to properly come together, an often difficult task. Forcing the fitting increases chances of a leak.
4. As noted in previous posts, new rings are essential.
5. The spring clip on the RW pump is there to secure the plumbing and pre-load the seals
6. Note that there are 2 types of seals. One is the square one we've been discussing, used on the tubes with a bulge about 1/2 inch from the end. The other is a C-section ring that fits on the end of flanged tubes. Don't mix the two up.

I have found that being patient and following the above works, and once sealed, the system stays quite leak-free for a long time.

If you still have leaks, carefully re-inspect the tubes themselves and the sealing surfaces for debris or damage.

[GordMay]

Good advice, especially from tkeithlu and jamhass.

[sailah]

Faced with that situation of an unacceptable sea water leak at the pipes, and if I can understand the situation it is the pipes sticking out of the pump body, and there is no way to get a good seal with the current setup...

I have 2 possible solutions that I would consider.

1: I'd need to determine how the pump is made and wall thickness of the pump tube bores but it looks like you might have enough meat there to simply tap the pump body for NPT threads. Then you simply thread in hose barbs with thread sealant and replace the bronze tubes with hose and hose clamps. This would involve measuring the tube bores with a caliper to see what the diameter is, and if this matches up with common NPT thread drill sizes. If yes, great, if not, you'll need to set up pump on a mill or lathe and bore them out to the correct size before tapping.

Or solution #2...

I'd buy bronze pipe barb nipples with a sufficient thread size to permit machining off the fitting threads with a lathe to a slip fit. So if the diameter of the pump bore for the tube is 20mm, I'd machine to 19.85mm. Clean out the pump after I removed it of course and remove all bearings and seals. Then flux and braze the fittings to the pump body.

Replace the bronze pipes with hose and hose clamps.

This would be a simple task for me since I have a lathe and torch etc but easily done by a machine shop. They might even be able to make the hose barbs since it's just a simple matter of the barbs, you don't need the hex or the threads.

Something like this: https://www.mcmaster.com/9431k13

[Cheechako]

Braze/solder in the pipes to the pump eliminating the seals? Or have a radiator shop do it. Cut a section from the piping and install good quality hose onto the remaining pipe portions? Or solder/braze in barb fittings?
or...
One wonders if cutting the pipes and putting hose in the pipe run each side would reduce vibration on the seals and the original seal type would not leak if you did that...

[jamhass]

PS:

Note on the link, that on the 2003T, the pipes leading to the RW pump have brackets to bolt them to the engine, thus eliminating the spring attachment across the pump. You could add similar brackets soldered to your existing pipes, which are just copper and easily soldered.

https://www.volvopentashop.com/epc/e...26/7726000_187

[Wulf]

Originally Posted by tkeithlu

Wow! You've done your best to seal that sucker. Evidently, the gasket and sealant isn't enough to make up for what ever curvature/flexibility there is in the plate. Assuming the others are similar:
1. Flatten the inside surfaces of the plates. Staple 1000 grit automotive paper on a smooth board, and hone the plate by dragging it down the paper.

All good advice but putting the paper on glass instead of wood ensures that you’re working on a truly flat surface. Don’t drag in a straight line, rather work it in a figure 8 motion to ensure no chance of scratches or unevenness on the surface being dressed. Also using wet/dry type of paper and a bit of water is most effective to prevent clogging the paper and maintaining sharp grit.

[hd002e]

Originally Posted by Pete7

Are you using new seals? we have a packet on board but they have gone hard so need replacing really. However, we don't have any leaks.

What is the thin wire clip for?

Pete

The wire clip is to gently aid the pipes into the pump, not enough to keep them sealed.

I hesitated to get new seals this time around because with the heat exchanger I got a set of seals for each fitting and they were so badly leaking that I figured it would not make that much of a difference here either.

[hd002e]

Originally Posted by tkeithlu

Wow! You've done your best to seal that sucker. Evidently, the gasket and sealant isn't enough to make up for what ever curvature/flexibility there is in the plate. Assuming the others are similar:
1. Flatten the inside surfaces of the plates. Staple 1000 grit automotive paper on a smooth board, and hone the plate by dragging it down the paper.

2. Check that the pump face is flat. Clean it and put the flat plate against it.

3. Use washers when you tighten the screws to distribute the load and keep everything flat.

4. Use a thicker gasket. Get some automotive (same trip to auto parts store) gasket paper, and cut new gaskets. Ask us if you don't know how to do that.

If you must use goo, use thin layers on all four mating surfaces, screw in place but wait 24 hours before tightening the screws.

Great suggestion on waiting 24 hours for the sealant!.

I did not use sealant on the pump cover, it is silicone grease as recommended by the manufacturer. I am glad I do not have any leaks around the cover. I actually had a brand new cover machined out of bronze stock and it is thicker than the original, there is no warping and I am very happy with it. Cost less than 8 USD for the whole thing in Turkey.