Sealing The Sump

[joelpsmith 1]

I've just taken my sump of to get it re-sealed and hopefully fix a leak. Since I've removed the aluminium spacer plate and cleaned it up I've noticed it is pitted slightly in a couple of places on both sides.

 

Firstly, what might have caused this? and what can i do to stop it happening even more. And also is it going to be best to get it skimmed before refitting, or am i likely to get a decent seal again just leaving it how it is?

 

Thanks.

Joel

[Goliath 94]

I dont know what could have caused the pitting. which side it the pitting on? the gasket side or the sealer side?

 

I dont think you should need it skimmed, you should be able to get a perfectly good seal using the correct gasket sealer.

[dcc 855]

ive not really noticed this i must say, but using RTV really worked well on my sump.

[CosKev 16]

I used gaskets on both joints with a slight smear of Loctite gasket maker

 

Also IMO use thread lock/seal on the bolts

 

Just clocked up 1100 miles since 10th December and dry as a bone

[Cameron 16]

Didn't work on mine, I "fixed" it 4 times using different makes or RTV 3 times and trying a fibre gasket once. Still leaked like a bastard.

[joelpsmith 1]

The pitting is mostly on the top side where it had been sealed using a standard silicone sealant. Could it be the silicone reacting with the aluminum that's causing the pittng?

[Miles 331 1 Cars]

A good quality RTV does the trick, I use the Wurth one but is trade only.

 

The rule is, Alloy sumps get sealent, Tin sumps get a gasket.

[midnight motorsport 0]

A good quality RTV does the trick, I use the Wurth one but is trade only.

 

The rule is, Alloy sumps get sealent, Tin sumps get a gasket.

 

ill second that, metal to metal, ie spacer to block, sealant only, then, if you have alloy sump again sealant only, tin sump, gasket and poss a smudge of sealant,

 

as for your pitting, i would not worry too much, if you use a good sealant and the surfaces are clean and free of oil/grease the sealant should take up any differences in the material, :-), But please remember, no oil/grease on the surfaces means NONE!!, dont wipe it clean with a cloth and expect it to seal, you need to clean it with brake cleaner, and dont even touch it with your fingers!! sealant will not stick to oil, and even the grease from your fingers will do this!! bit extreme. but trust me if you dont want to keep sealing it up, it must be Clean!! :-)

 

i normally use loctite sealant, the white one,(cant remember the number off top off my head)

or, and i hate to say this, but if you go into vw and ask for sump sealant for there alloy sumps, like a 20v engine, they have a specific sealant (it is also white). and it is amazing stuff!

or finally,

if i am felling rich, i use a sealant called 'proseal', but is fairly hard to find, and is quite exspensive, but is hard to beat!, we manage to seal up our vintage sheds with this stuff, so they acctually hold oil!! lol, and they never did that from new!!! so 70-80 years later thats pretty good!! :-)

 

i have never had a sump leak using any of these sealants,

 

i also use the white sealant (loctite), or proseal, to seal my (petert) copper head gaskets around the waterways, and again have never had a leak to date, really good stuff IMO

 

cheers

Edited January 10, 2009 by midnight motorsport