Hello Gents,

After replacing the water pump ~2years ago and many hours of trouble free operation, my water pump gasket blew out while pulling into my driveway. I had the same phenomenon occur shortly after install on the thermostat housing. The paper gasket blew once the car was warmed up. The gaskets I'm using are what is available from Moss, fairly thick teal colored paper. For the thermostat housing I installed them dry and for the water pump I used water pump gasket sealant from Permatex. I reinstalled the thermostat housing with just the water pump gasket maker and it has been trouble free.

So question is - am I doing something wrong with these paper gaskets? I'm about to dig in and take the water pump out but I've lost a fair amount of faith in these paper gaskets and am leaning towards a silicone only approach. Any thoughts?

Cheers!

 

Engine size?

 

I have the 5.3 V-12, apologies.

 

OK, this happened to me years ago. In my case it was caused by the securing bolts backing out. Try refitting with a new gasket, the best you can find, and using loctite on all the threads. It cured it for me.
A genuine gasket like this sort
https://www.ebay.co.uk/itm/125653458...3ABFBM4rnX2vdm oor
https://jaguar.oempartsonline.com/oe...gasket-ebc9629
and dress it both sides and the metal surfaces with permatex aviation form a gasket no 3.

 

Cheers Greg.

That looks like the gasket I have on order currently. I guess I shall see if those bolts worked its way out when I remove the rad for reassembly. Hopefully that is the case here. Is silicone/water pump sealant only a bad idea? Just curious.

Thanks!

 

In my opinion in this application, yes. There is high pressure in the pump and the seal only has to give a little to leak, and it all is clamped very tightly. Silicone can be good in trans pans for instance, Grant swears by it, but in that case there is no pressure and the pan bolts are not tightened hard, juts finger tight, leave overnight and another turn. But in this application gasket plus form a gasket works, plus loctite on the bolts and studs, both ends of the studs if one or more come out.
https://www.permatex.com/products/ga...t-liquid-4-oz/

 

Roger that. I'll wait for the gasket to arrive and order the correct sealant.

Pump is now out and I can confirm that it was specifically the nuts on the flange part of the water pump housing underneath the idler puller that were loose and where the gasket blew out. I don't recall the correct procedure here and the repair manual is not descriptive: because of the two part nature of the pump, do I need to remove the water pump pulley in order to replace the gasket between the halves? I see that there is a special tool required but I did not have access to that last time and don't recall what I did. Do I just screw in bolts to press it out, reassemble with sealant and gasket and then press it in using a press?

Also, can I replace the pozidrive screw with a suitable bolt? Not sure what the purpose of having a screw there is and would like to ensure correct torque.

 

You will have to pull the impeller off of the shaft/bearing assembly to replace the gasket that is between the pump halves. If I recall when I did mine, the impeller had threaded holes and I used a small gear puller that I had…be sure to note how far to press (pound) the impeller on for reassembly.
Don’t know about the Pozidrive screw; I had a correct fitting bit so reused it.

 

You have to keep the pozi screw otherwise a normal nut fouls something, I forget what!. Maybe a countersunk Allen Key headed one would work fine, if you can source one. I think , repeat think, the threads are either UNC, or Metric, easy to check that.

 

When that pump is off, look, and look again, at the timing cover mounting face for any pits and other imperfections.

Most I have dealt with are not 100%, and that is an issue. That is why I use the HiTemp Grey RTV (JB Weld brand) as a dressing (smear in some lingo's), set the pump up, and a tad over finger tight, WAIT, as per the label on the tube, then firm up about 1 turn more, NO Gorilla stuff, as that will split the gasket.

After an hour or so of running, PITA stuff is to check the nuts/bolts/screw for firmness. Your car, your call on this one.

Lower the pressure cap to 13psi, it makes a world of difference.

Gregs #3 Permatex, awsome stuff, and I use it a lot, just that the RTV sat better with me on that area.