Replacement windscreen washer pump is leaking

[billwin]

Spoiler

 

The original washer pump was leaking from the body of the pump so I bought a replacement on the internet. Fitted it and found it leaked even worse from a vent hole in the body. The old pump did not leak from that hole. Thought it must be faulty and the supplier sent a second pump. But it too leaks from the same vent hole. Am I just unlucky or is this the wrong pump? The part numbers listed said it was correct. Photo attached showing my test for leaks on the second pump.

[J.R.]

Do you have an open unobstructed output from the pump? You appear to be holding something over the outlet which might block it, at the minimum it should have an orifice equal to the sum area of the washer jets.

 

It could be a pressure relief port, 3 pumps leaking from the same area sounds like blocked jets or tubing.

Edited 21 December, 2022 by J.R.

[billwin]

Just to clarify, the pump is not actually pumping in the above photo so no pump pressure on the outlet ports. It's simply a static head of water similar to the water in the washer reservoir and it passes straight through the pump and leaks out of the vent hole. The original pump did not do this. I'm covering the two outlet ports to prevent it syphoning out of those outlets which would be normal, I think.

[TMB]

Must be a faulty batch of pumps.

[billwin]

As the supplier has refunded and doesn't want the pumps returned, I've started to dismantle one to see what's wrong. I'm that sort of person. The vent hole is in the motor section and water has got past the impeller section into the motor. Clearly the seal is not fit for purpose and even if it didn't leak to the outside, the motor would eventually fail.

[varooom]

Do you have the factory fitted pump number?

[skomaz]

Can you mix and match parts to get a working one out of the three you have?

[TMB]

2 hours ago, billwin said:

I've started to dismantle one to see what's wrong. I'm that sort of person.

 

Me too, I love a good old post-mortem. There are some rubbish parts out there.

[TMB]

Part number should be 1J6 955 651

[varooom]

1 hour ago, TMB said:

Part number should be 1J6 955 651

Thanks, I was busy today, that allowed me to put the part number in and check for supersessions, so it seems there has been.

 

@billwin

 

 

So the "new" pump part should be 1K6 955 651 plenty out there on eBay/Amazon etc

Price seen here is at the dealers, so best avoid and locate one youself.

[billwin]

The original pump is 1k6 955 651. The eBay replacement quoted the same number so should be the right one for £8. 

I did find the old pump could be disassembled easier, the cylinder on the side could be pulled off, rubber O rings sealed the connection pipes. (The new unit is all glued) Then I could split the cylinder where an internal seal was leaking causing the initial problem. Wrapped a bit of PTFE tape around it, pressed everything back together and it seems pretty water tight.

 

[nta16]

Please note - I am not a mechanic or expert in anything.

 

Well done on the repair.

 

Parts quality, or lack of, becomes even more noticeable as the car gets older. 

 

23 hours ago, billwin said:

Wrapped a bit of PTFE tape around it, pressed everything back together and it seems pretty water tight.

There are two thicknesses of PTFE tape (that I know of, there might be more I don't) "water" and "gas" (the thicker one) makes no odds which you use on water jobs other than if it's too thick, or thin, for the job.

 

Edited 23 December, 2022 by nta16
ETA: Please note - I am not a mechanic or expert in anything.

[billwin]

Just to conclude this post. The pump motor is separated from the impeller using a rubber bung to keep the water from reaching the motor. I think this should be a fairly tight fit while still allowing the motor shaft to spin. In my new motor the bung slips out fairly easily and doesn't make a water tight seal. I'll try wrapping a couple of turns of PTFE tape around the bung and hopefully produce a working pump that doesn't leak.