300Tdi P gasket!!!!

[Felix]

Hi guys, just replaced the P gasket on my 300Tdi with the proper tin crush type. However it is still leaking (but substantially less now). I'm guessing this may be due to the mating faces not being 100% flat due to corrosion, as the bolts are tight and were done up in the right order and the gasket is sitting correctly.

What have people done here? Use a silicone sealant or flange sealant? Non-hardening (Permatex)? Bluemaxx?

Any help appreciated. I hate doing jobs twice. Especially those involving coolant. I hate coolant!

[steveG]

Been years since I've had to do one, but will be doing one again shortly.
From memory there was a stud in the block that was a PITA to clean around, but my stuck in my memory as it would definitely cause distortion/leak if you didn't get all the old gasket off.

I'm a fan of Permatex #3 for cooing system joints, but haven't used it on the metal P gasket.
Seems to do a good job of minimising corrosion as well as sealing (and doesn't go hard after a few months in your toolbox either).

Steve

[camel_landy]

FWIW - My money would be not getting all the old gasket off. :(

However, it's probably also worth confirming you have the proper bolts in there as they changed the length when they changed to the ally 'P' gasket.

M

[roverrescue]

The WP housing and mating surface of the front cover can get small areas of pitting corrosion. Especially prevalent about the very lip of the chamfer.

Need to be careful that the mating surface is flat and free of any pitting. In the past I have built up pitting with 'metal epoxy' and then surfaced. A new WP goes a long way to get a clean surface on the pump.
Then with the metal gaskey using a jointing compound (choose your posion) goes a long way to making the WP leak proof.

Also a good suggestion to replace the long bolts when you do the job. Once the coating sacrifices away the bolts corrode very quickly and will only lead to drama down the track.

The metal P-gasket (like MLS head gaskets) need flat clean surfaces to work...

Steve

[Kappa130]

I replaced gaskets , bolts, tried various sealants and nothing worked %100. Some of them slowed it up but the weep was still there .

In the end i used a large piece of glass layed on the bench and some bearing blue to check the flatness of the large alloy bracket. taking extra notice of the mounting pads that pull up against the cast iron block and the area where the p gasket seals .
This was warped to all buggery .
I then used a flat file to get it close (some pads need over 1mm removed from it) and finished of the lot with a large rub stone . Checking the flatness as i went .

Re-assembled it with some CAT sealant and never had another problem with it .
Hope this helps ,
Even when you pull it apart , at least check the mounting pads and gasket face are all level as this will save you a bucket load of time and skinned knuckles in the long run .

[Felix]

I'm thinking it is due to the fact there is some pitting on the surfaces. I did get all of the gasket off and was hoping it'd just... work..Silly me.

I've been checking it quite often (immediately after driving, and before setting off) and I think the leak is so small that it is now evaporating before it gets anywhere.

I'll do it again when I replace the water pump (along with all of the bolts), use some sealant this time and check the flatness of the housing. I have access to a mill so shouldn't be a problem.

[roverrescue]

Dont mill too much.
It will alter the tracking of the WP pulley and possibly lead you to the gates of squeel city!

Depending on flatness and pitting I would think building up and machining back a better option than simply machining down to a flat face.

Sounds like your onto it though.

S

[lro11]

I used the gasket supplied in the vrs kit and some loctite flange sealant worked perfectly

[Jode]

I used the gasket supplied in the vrs kit and some loctite flange sealant worked perfectly
Is that the metal or "paper" gasket?