Jump to content

Sump Gasket - latest thinking please


Recommended Posts

Hi Everyone

 

In an effort to stop a few drips, I have just replaced the sump gasket on my 4A

 

Having put it all back together again, I still have a couple of drips

 

I used Wellseal for the gasket sealant

 

Does anyone have a view on any alternative?

 

I feel I ought to try again but should I just feel lucky that I have a couple of drips anyway and quit whilst I'm ahead ?

 

Thank you for any thoughts

 

Nick

Link to post
Share on other sites

The cause is the tin sump fitted to the engines (you may have guessed ?). Prior ham handed owners will have overtightened to try and prevent leaks and made the leak worse by deforming the tin more.

Remove the sump and "dress" the sealing face of the sump in a vice using a former. (Tap the deformations out using a smallish hammer against a flat and square large metal object (sledge hammer head if desperate) held in the vice). Use a straight edge down and across the sump and see where any dips are (normally in between bolts) and then straighten them up as just described. Wellseal although an excellent shellac or sealant for close fitting faces (ie bottom of the Liners) doesn't do the job here, being too thin and having poor gap sealing properties. Blue hylomar applied as per their instructions and the Grey Locktite (what's that noise ? it's Ash with it's correct number (he uses it a lot) and will help with it's identity), will do the job nicely. Tighten the sump up gently and loosely until only just touching the surface of the engine block and allow the sealer to go off, when cured tighten the sump up by hand and torque wrench to the appropriate figure, not a lot from memory about 18 lb ft torque (check this).

If you wish to fit an alloy sump this is one advantage they definitely have being flat and with a greater resistance to deforming, silicone the gasket to the sump and after allowing the silicone to go off bolt the sump up to the engine without any sealer on the engine block. The block face is flat and square and should seal against the dry gasket fine because of it having no deformation, it's then easy to get off and you can leave the gasket on the sump. You can use the same system on the rocker cover also if you have an alloy one.

 

Mick Richards

Edited by Motorsport Mickey
Link to post
Share on other sites

Hi Nick,

this is Ashleys reply about my gearbox leaks "Loctite 5699 because the war is over and progress has been made in the last 68 years. "

 

It is a thick gloop that should fill most unevenness.

 

My sump has Blue Hylomar around all the sump bolts as the spring washers do not form a good seal.

 

Roger

Link to post
Share on other sites

As Roger would put it: "what have you started here ?". 4As crankcase pressure management can be quite challenging as they don't have the vent pipe fitted on the bloc like the 4s so the only crankcase pressure outlet is through the PCV valve which to my experience and liking is far from satisfactory. There I said it....

Link to post
Share on other sites

Thanks guys, Blue Hylomar on everything or on the joints? and then additionally Loctite on the bolts or will the Blue Hylomar do the lot?

 

Sorry, just need to be clear as I dont want to do be redoing again if poss! Not one of my favourite jobs for some reason

 

Cheers, Nick

Link to post
Share on other sites

Either Hylomar or Loctite used on the sump and a squidge (twice as much as a tad) on the neck and underneath the lock washers on the bolts should stand a chance of keeping it oil tight.

 

Mick Richards

Link to post
Share on other sites

Always the optimist Roger, lol. :lol:

 

Mick Richards

Link to post
Share on other sites

Morning all

 

Well I followed Mick's advice and offered the sump up to the block and gently tightened up the bolts.....all good so far!

 

Allowing time for the sealant, to cure I then torqued up the bolts 18/19

 

As I did so, I noticed a couple of areas where the gasket had started to bulge out a bit as the sump and block came together

 

Damn, that's going to leak I bet!

 

No time to start again now, so carried on hoping enough gasket in place

 

Added oil and started her up.........no leaks!!!.........test drive........no leaks.........

 

Will leave overnight and pray for no leaks

 

Is that usual for the gasket to not fit properly or could it be the distortions in the sump casing?

 

The gasket did look a bit big in some areas when I was applying the sealant almost as if it needed trimming

 

It doesn't look that pretty but if it seals that'll do til the "drip, drip" starts again

 

Cheers, Nick

Link to post
Share on other sites

Hi Nick,

 

Normally it's the ripple in the tin sump and the distorted areas that cause the bulging effect, if you got it pretty close to flat the Hylomar should have enough "gap capacity" to keep the oil in, ( we hope). I take it unlike the alloy sumps which I wouldn't use Hylomar on both sides of, the tin sump has a layer of Hylomar on both faces ?

 

Mick Richards

Edited by Motorsport Mickey
Link to post
Share on other sites

Most of these issues can be blamed on the dire gasket quality; there is nil conformability in the majority of those currently available & they will sometimes part at the points where the bolts nip. There's no need to gum up the majority of the threads as long as there is sealant on the inner side of the gasket- that only applies to bolts which actually penetrate the crankcase, three or four methinks.

Incidentally, those with alloy sumps can dispense with a gasket altogether, as per contemporary practice; the sealant to use is an OEM spec RTV called Dyko, which is excellent & has a multitude of uses.

Digression time (sorry): Loctite & Würth each supply sealants that replace thin paper gaskets & I have not used any gearbox gaskets in years thanks to these admirable products which in fact add considerable rigidity to finished assemblies.

PM for more info if required.

Incidentally, the engine in a certain highly successful contemporary TR6 racer, (built by yrs truly), has but one gasket in it: the head, of course, & is completely oiltight.

Link to post
Share on other sites

Thanks guys, I have been out for another test drive.....15 miles or so and when i got home had a peek under the sump to look for a drip or two !!

 

Not a drop, so although the drip tray and newspaper are in place I'm hoping all will be well in the morning

 

Just need to stop one of the pushrod tubes from weeping oil next ......maybe i'll have a leakfree TR one day !

 

Cheers everyone and thanks for your help

 

Nick

Link to post
Share on other sites

Give me a cork sump gasket anyday and apply Wellseal. I was lucky enough to pick up an alloy sump at a bargain price.

A cork gasket compensates for the uneven surface of steel sumps. Mick is quite right, overtightening of the sump bolts

when the thin paper gasket is fitted destroys the seal.

 

Tom.

Link to post
Share on other sites

Hi Nick,

without a good deal of dismantling you will not seal your push rod tube.

 

The ends of the tubes are swaged into the head at both ends. I don;t know if any sealant was used.

To ensure a good seal you would need to remove the tube and refit with new tube and sealant.

The swaging could be done using a large ball bearing.

 

If you simply clean the outside (head insitu) then more oil will follow due to capillary action.

If you try to seal over the top after cleaning you may be lucky but oil is messy stuff and doesn't like to stay put.

 

Roger

Link to post
Share on other sites

FWITW I straightened out the sump flange, used a cork gasket (TR shop) stuck to the sump using wellseal, & used no sealant, but grease on the top surface.

No leaks after 13 months. My only oil drips come from the breather pipe.

 

Bob.

Link to post
Share on other sites

Ditto with the rocker cover cork gasket, only I Welseal it to the head, & apply grease to the top surface.

Advantage is that you can re-use the gaskets over & over because they will always contact in the same place.

 

Bob.

Link to post
Share on other sites

FWITW I straightened out the sump flange, used a cork gasket (TR shop) stuck to the sump using wellseal, & used no sealant, but grease on the top surface.

No leaks after 13 months. My only oil drips come from the breather pipe.

 

Bob.

Hi Bob, you mention a breather pipe my TR4 does not have a breather pipe unless you are talking about on the rocker box cover breather to the inlet manifold. Should I have one? I did see a post on the 710 filter thread where somebody (sorry can't remember the name) did mention they had to remove the snorkel breather to remove filter. But my block does not seem to have any opening there other than for the fuel pump and filter housing. The engine does seem to be correct by the engine number and is closeish to the commission number, but I know that can be a bit of a dark art and was most likely just put an engine in the queue to the production line to be fitted in an approximate order.

 

Mark

Link to post
Share on other sites

Oh and just to add a point, I recently went under to replace the paper element filter and discovered that my sump has every other sump bolt missing (thanks to the PO for that or his monkey), some I'm feeling quite smug it does not leak, but maybe that will change if I every have to remove and discover what has been used. Think I know as I can see the familiar orange sealant has oozed through the missing bolt holes.

 

Mark

Link to post
Share on other sites

Mark, it was yours truly that mentioned about the snorkel breather bracket getting in the way of the Purolator oil filter canister. My 4A engine was originally fitted with a PCV and the snorkel hole was blanked off with a core plug. As I didn't want a PCV, especially because my Offy valve cover doesn't have a take off, I removed the core plug (it's right by the fuel pump) and fitted a snorkel. I don't know when they changed over from snorkel to PCV but I think that 4As were all fitted with a PCV and had the snorkel take off blanked.

Link to post
Share on other sites

Ah cheers Pete, I think I must have subconsciously assumed the core plug went into the cooling system (as I'd normally expect) and not the crank case as it does in this case or maybe they changed the block casting, I'll have to check when I get home, intrigued now. My TR4 is April 64 so is a late one, so will probably share some minor similarities with the TR4a.

 

Mark

Link to post
Share on other sites

my sump has every other sump bolt missing (thanks to the PO for that or his monkey), some I'm feeling quite smug it does not leak,

Mark

 

I think that goes to show how right Mickey is about not overtightening. Although GoK what torque the Monkey used.

 

I think that official torque for sump bolts is 16-18 ft-lbs. Most people don't have torque wrench that reads that low, so I'd say, hand tight plus a tweak. "Hand tight", as tight as you can using only wrist/forearm strength, with a 6" spanner, about 12ft-lbs. A tweak of shoulder strength, less than a quarter turn, should be about right.

John

Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Restore formatting

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.

Loading...
×
×
  • Create New...

Important Information

Please familiarise yourself with our Terms and Conditions. By using this site, you agree to the following: Terms of Use.