Head gasket job

It can be done without removing the pony, the gasket that goes between the pony and the head is the toughest part to get right. It has been a while since I did a 4400 head but I remember sliding that gasket in after the head was down but not torqued, I think we pried the gap open and slid the gasket in, it was lubed up with RTV and it has a metal frame in it to keep it "shaped up" during this process.

I just finished the head on my D6 9U and I used aviation permatex type gasket sealant. It now has no leaks, previous it had the same symptoms you describe. The sealant is the easiest I've ever applied yet also the sloppiest of stuff, but it works. I use it on all major assemblies and can't complain about leaks once it cures.

Yes all the CAT engines with the exception of the 3204/3208 have wet sleeves. It is not likely you would HAVE to disturb the sleeves changing the head gasket. They are usually stuck in the block pretty good!

On the other hand it is common to have seeps along the head gasket line that are only an unsightly mess, never causing any problem.

**********If you take the head off you need to tell yourself "my engine runs well and absolutely does not need an overhaul" about every thirty seconds until you have it buttoned up again! Above all, do not feel the cylinder bores......better yet don't look at them either! It is a slippery slope that starts with the head coming off for something minor and leads directly to a complete overhaul!********

Julian, it is not unusual for older head gaskets to need re-torqueing and it can be done without removing the head, my RD4 had those symptoms you describe and it was a simple matter of slightly undoing each head nut about 1/8 of a turn then re-torqueing them to the correct spec, try that first before pulling the head off.

With the help of "Eddie" we refitted a reconditioned head on to my D4 7J diesel motor with the pilot motor in place, it can be done but it is a very tight fit.

Try re-torqueing the old head gasket first.
Mike

Hey Julian, I just notices you are in Warrington, UK. I have just arrived home from Tom Atherton's working event today and wondered if you were there, if so it's a shame we missed each other.
My D7 7M also has a very slight weep of oil from the front cylinder head gasket which appears to do no harm, so as CCjersey says maybe best to leave well alone.

My D2 gasket weeped really good till I retorqued also. Taking the head off as others have said doesn't require anything else to be disturbed except for loosening the pony so you can apply a slight tension to slip the new rubber gasket down in there. Like Mike explained, Someone a long time ago suggested sandwiching it between two thin metal plates, then slipping it into position, sliding each plate out, one at a time.
(loosening and wedging the pony away worked for me)
I believe I lubed it with RTV to assist sliding the plates out on the theory that it would help it seal if I deformed it.

Thanks for the replies. Some good advice and I'm going to retorque the bolts first and see what happens, it does make good sense if it saves a lot of work although I rather like doing these sorts of jobs. Anyone have a torque value handy (other than three white knuckles) as my literature is stilll in boxes following a house move?

John, I have moved up north a while ago (Cumbria) I'll update my profile. Glad to hear Tom's do is still going, I though he had jacked it in.

Now then I have an old Fordson water washer tractor with a hell of a noise from the gearbox, another resto job for winter....

Julian

Hi Julian. - torque for head nuts , if it has hardened washers and nuts 1/2" nuts - 70 lb ft -- 5/8 nuts - 140 lb ft. Valve clearance ( hot ) 010" in) Early engines were 58 & 130lb ft Regards Al

I thought those specs were in the Technical section, I know "Eddie" has posted them several times, the sheets cover all the Cat engines for torque and sequence.