Peugeot 504 head studs - do I use lube/sealant?

Pug72

Active member
Fellow Frogger
Joined
Feb 11, 2013
Messages
531
Location
Brisbane
Hi all

I am about to install a new head on my 504 (petrol 2 litre). The Haynes manual does not mention stud lube or sealant on the head stud threads.

Is this required to ensure correct torque is achieved? Do the studs need sealant (are they entering into a water gallery?)

I'll post pics of the tear down/build up shortly

Thanks heaps
 
My copy of the 504 factory manual says:
Smear the bolt threads with tallow, fit the flat washers and tighten the bolts down moderately.
Warning: The bolts must turn freely.
Fit the rocker shaft support nuts.
Two methods of final tightening are then given, depending on liner type (XM vs XM1, XM2, XM7)
 
The head bolts do not need to be sealed. They dont pass through any galleries.
 
ok thanks heaps

I don't have access to Tallow right now, is there an alternative - say engine oil?
 
Try some teflon anti sieze, galling etc. Just a little
 
I use copperkote, lithium grease, or any other highist temperature anti seize lubricant.

Just a little, enough to fill the threads from root to crest.
 
Ok thanks everyone. I see Permatex make an anti-seize so I'll stop in to Repco tomorrow and grab a tube.
 
I just use a light spray of wd40. Could be better options but have never had any problems.
 
Last edited:
No sealant needed on 504 head bolts.
I have always used moly grease on the bolts, lightly coated all over and under the bolt heads.
You will have noticed on removing the bolts that the shanks can be rusted/corroded hence my preference for moly [graphite] grease.
I have a 504 head here where it has been removed with most of the bolts seized in the head. They have been impossible to remove unless I can press them out. I can only think if the bolts had been greased by whatever they would have been released normally.
Fortunately the head is in surprisingly good condition otherwise, water jackets, water pump plug etc.
 
^ Would heat help removing them ?

Have you tried smacking the bolt heads vertically with a middling-sized hammer, to shock off the rust binding the threads ?
 
No sealant needed on 504 head bolts.
I have always used moly grease on the bolts, lightly coated all over and under the bolt heads.
You will have noticed on removing the bolts that the shanks can be rusted/corroded hence my preference for moly [graphite] grease.
I have a 504 head here where it has been removed with most of the bolts seized in the head. They have been impossible to remove unless I can press them out. I can only think if the bolts had been greased by whatever they would have been released normally.
Fortunately the head is in surprisingly good condition otherwise, water jackets, water pump plug etc.

Soak the head in mixture of molasses and diesel fuel for a week or longer.
 
Beano,
Have yet to try heat. Fortunately there is no pressing need for the spare head.

robmac,
What is it with you "Wise Men of the East?" All this talk of Tallow and Molasses !
Seriously, thanks for the tip. Have heard of molasses being used by restorers to remove rust from panels and parts.
 
Top