The original rear main oil seal in that engine is a rope-type seal. If your mechanic is replacing it in the vehicle with another rope seal, it's hard to no have them leak. Victor makes a rubber lip-type replacement seal for that engine, part # JV748. Try that and see if it helps.

tom

 

292 Y-Block Oil Leaking

Thank you sir!

we tried the rope type 1st then the neopreme Lip type and neither did the trick - I'm almost thinking of magna-fluxing the block for an external crack - but it seems coincidencial that it never leaked that much until the big "blow out" and now, even though it is better, I still can't seem to plug up the wound!

Thanks for your reply

 

Old Ford guys tell me that is the curse of the Y block. There is a fix, I am told that requires taking the block and crank to a machine shop. We have a 312 in the 56 Tbird we are taking to the exhaust man tomorrow. We are expecting it to leak in the future, but so far the start up and tuning in the garage floor has been leak free.

Trees

 

The recess that the seal fits into was not always perfectly machined in the older rope seal blocks. That didn't matter 'cause the old rope seal was very forgiving in that respect. Replacing it with a rubber type seal can sometimes fail because the rubber can't conform like the rope did. I think your best bet is to pull the engine and the crank to properly install a new rope seal. It's tricky enough to do it on the stand, much harder to do it right in the vehicle or with the crank in it.


tom

 

Thank you all! It sounds like the old 292 has to come out of the car - We will do what we must do! Thanks again!

 

Y-block rear oil seal

I am having the same problem with rear seal. I bought a long block from S&S engines and it started to spew oil in a spray pattern. I replaced their new neopreme seal with another new one to no avail. The Napa engine builder told me to go back to the rope as some engines just don't seem to hold the oil back with the neopreme seal. I did notice the neopreme slipped into place very easily and thought maybe the rebuild had opened up the tolerences ( through honing and polishing ) and their might be an oversize neopreme seal available. Has anyone explored this possibility? Is their a neopreme seal available that is slightly enlarged?

 

Dunno about the oversize neoprene seal, but the old "back in the day" lanyard for replacing the rope seals was iffy at best. It gained improvement over a bad leak, but in my experience "also back in the day" is that removal and proper replacement worked best.
PatM

 

Y block experts ?

There might be more info on the Y block forums, I have a Lincoln Y in a 46 parked behind the Barn i got in a trade, I have never tried to start it. I met a couple guys at Bonneville a couple years ago running a Ford Y block and they Knew all the tricks, gun drill , thread and add support studs to reinforcecombustion chambers, Carrol Miller"s use of a strobe lite to tune the valve train , More oil the the rockers, etc. I never had a Y that did not leak a little bit of oil,

 

One thing to remember is that today's rope seals aren't the same as the old ones. The old ones had asbestos in them and seemed to work better.

tom

 

in car repair,

The in car repair for the upper half was to use a corkscrew tool to pull out the old seal then a woven wire chinese finger trap type tool to pull the new seal into the grove, use a razor to cut it off with the specified overhang then use a tool to pound the seal back into the grove, the problem was to getting enough back into the grove, install the cap , then remove and trim off the excess, usually after a few miles you found out you didn't get enough rope pounded up when you started getting drips.

 

Is the oil fill cap clean ? Is the filter in the road draft tube clean ? If these motors can't breath they leak . Is the shaft groved , did you polish the shaft with 220 or finer emery cloth , is the rear main bearing good or is it showing a lot of copper ?

 

I'm not so sure that these old blocks can be successfully resealed without dropping the crank out. Many of these blocks have a spike in the apex of the seal relief which is there to prevent the seal from rotating after installation. Being sure the spike's base is clean and clear of any debris and that the new seal has positioned properly can be an issue.
The crank has an integral slinger be sure the oil return hole/vent in the bottom of the rear main cap is open. Slinging oil off the crank greatly reduces the work of the seal so be sure this feature is there and able to work.

The seal needs to be pounded into place on the upper boss and into the rear main cap this is best done with a mandrel of about the size of the crank, these used to be part of a mechanic's tool box today you can use a piece of large diameter pipe that is close to the crank diameter in the seal area. There seal ends need to be trimmed leaving about 1/32nd to 3/64ths on each side of the top and bottom halves so there will be a crush fit upon installation. This has to be done with a very sharp blade for a clean and stringless cut. There must be a crush fit at this spot and there can be nothing that gets into the machined faces where the cap will register to the block. This usually means putting the cap on dry, torquing it up, then removing it for inspection to be sure no seal material is on the mating surfaces. Then I like to put a hit of non-hardening Permatex on the top to bottom interfacing edges of the seal before buttoning it up.

Bogie

 

Good place to check in at is here: Y-BlocksForever Forum most prefer the neoprene seals."Fords don't leak, they are just marking their spot!" :mwink: In the past I have seen some with a groove worn in the crank which can be an issue,not real common but with a Y-block that has not been in production for about 50 years anything is possible.

 

I use anaerobic sealer on the parting line of the rear cap to help seal up all types of rear mains.

 

The neoprene seal on these Y-blocks are easy and pretty bullet proof and if they do leak is a wet spot and not a drip in my experience, unless someone just totally clustered up the new seal and it dripping good, there is a freeze plug just above that area that when it goes, it leaks like crazy.


Simple to figure out, clean area best you can, have someone with a drill priming oil pump and get pressure 75 or more up to 100 and you will see where leak is coming from real quick, when laying under there, bad news is on auto you need to drop trans, to reach freeze plug, not sure about a manual.
Now that I think about it, with an auto, I don't think you can, even see the plug with trans connected but if its leaking you will get a face full of oil real quick, been there done that 2 too many times.

 

Is the crank seal leaking or the funny strip seals on each side of the
seal cap? Did you install the finish nails that tighten the side seals?
I have found to leave just a bit extra seal when cutting the ends helps.