Best way to fix the oil leak at front of block?

[RobT]

Like most Triumphs I have known, my TR250 has an oil leak at the front of the block. Since I have the radiator out for a re-core, and am overhauling the front suspension over the winter, I am thinking of attacking the oil leak too.

Now it looks like the best approach will be to pull off the timing chain cover, front plate, and sump, and then replace all the gaskets and the crank seal. I also have a steel replacement of the aluminium saddle block that goes under the crank and ties in the front plate and sump. Using the steel unit is supposed to allow you to get greater torque and so a better seal on the sump and front plate at this point.

Does anyone know if replacing this and all the seals etc is possible with the motor in-situ, or am I likely just to make things worse by not being able to properly fit everything without having the motor out? Anything I should remember or good tips to making the front end leak-free?

Thanks,

Rob.

 

[gjh2007]

Rob, you have a PM

 

[Guest]

I'm interested for some info on this as well. I just recently got done doing an oil pump and bearing change in my TR6 and now the front of the motor is leaking worse than before I did the job. I replaced the aluminum saddle bar with the steel replacement also, and the sump gasket is new and seems sealed tight with hylomar. From what I can see now the leak isn't coming from the sump, but probably either the timing cover, front plate, or front main seal. Haven't had a chance to really get under there and dig around yet, so I'm not sure. I was planning in leaving this till the spring since the car isn't going to be driven much between now and then anyway. However, come spring I was planning on pulling the rad and most of the front of the motor and replacing all of the seals mentioned above, as well as doing some other things while in there like finishing my cold air kit and an electric fan upgrade. Anyway, I'd be curious what people have to say on replacing all those gaskets and seals and trying to make the front of this motor tight and leak free.

 

[trboost]

Re: Best way to fix the oil leak at front of block

Rob,
Since your 250 is an early producrion car the sealing block has been superseded. There was an early & late part #. The site used to be available on line but I can't find it any more. It really doesn't matter because both leaked, the second relaese was reinforced & used two more bolts to secure it.

Both blocks were soft aluminum. Special care has to be taken when tightening. Two bolt are shorter than the rest & must be installed in the proper location. I would use Holmar sealant. You don't have to remove the timing cover for this repair. Make sure the oil pan is not dimpled where the bolts have been tightened. Pay special attention around the wood wedges, again covering them in Halomar. The screws often strip in the sealing block, if this is the case I have had great success with Keenserts https://www.keensert.com/

I have seen new steel replacments on Ebay. I contacted the seller last year & he seemed like a reputable seller making an improved block.

Let us know if you need more info.

 

[RobT]

Re: Best way to fix the oil leak at front of block

Thanks trboost for your advice. I will probably remove the timing cover and replace the crank seal as a matter of corse. Is removing the sump and replacing the sealing block possible with the motor still in the car though?

Also Gary's suggestion via PM (I hope he doesn't mind me posting it here) was to check the PCV valve as this can block-up and raise the crank case pressure and force the oil out. A good tip, but since my PCV is long gone (crank case vents into air intake) it was not applicable to me.

Anyway if anyone has any other suggestions on fixing the front end leak, or using the steel replacement sealing block, I'd love to hear it.

Rob.

 

[trboost]

Re: Best way to fix the oil leak at front of block

As strange as it seems, it's really not a tought repair. It's the working on your back looking up that sucks. The oil pan is very easy to remove & full acess is there. Let the oil drain out completley & after you remove the pan put a drain pan down & let the rest of the oil drain off the motor or you'll get a face full of drips , it's torture /ubbthreads/images/graemlins/smile.gif

 

[Webb Sledge]

Re: Best way to fix the oil leak at front of block

My Tr6 also leaks from the front of the block. I'm not 100% sure, but I strongly suspect that the harmonic balancer was made just a thousandth or two to small for the seal that goes around it. I have tightened up all the bolts in the pan, front crossblock and timing chain cover and it still leaks.

 

[Andy Blackley]

Re: Best way to fix the oil leak at front of block

RobT: May I respectfully suggest that you still have a problem with crankcase pressure? Connecting the hose from the rocker cover to the airbox does not provide enough "postive" crankcase ventilation - you need manifold vaccuum for that. If you still have the stock intake manifold I highly recommend re-installing the stock PCV. Even though it was an early attempt at emmissions control it works. Its doesn't rob an once of power, and IMHO it works better than the setup on later cars that were connected to the port on the carbs behind the throttle plate. FWIW.

Eliminating excessive pressure will probably effect the leak with regard to its volume, not totally eliminate it, so the improved sealing block still sounds like a good thing to pursue.
I still have the Smiths PCV on my 250 and my front crank seal also leaks, but frankly not anywhere near enough to go to the effort of tearing it all down. My oil level hardly drops between oil changes and oil leakage is tolerable (for me anyways).

 

[swift6]

Re: Best way to fix the oil leak at front of block

If the front engine plate is warped, it will never fully seal and will be a constant slow leak under pressure. More like a seeping leak than a spray but enough to cause a persistent drip.

All it takes to warp this plate is the wrong timing cover bolt in the wrong hole. Some of the bolts are marginally shorter than the others. These shorter bolts do not thread into the block, only the front engine plate. If one of the longer bolts is put into one of the areas for the shorter bolt it will tighten up fine and keep the timing cover from leaking but will cause a slight warp in the front engine plate.

This can be a very big pain to fix! I've done it on four Triumph engines (fixed it, not caused it). First discovered it on a Spitfire engine. Repaired one on a Herald engine from an Amphicar and two TR6 engines. (The builder I used for my car and the engine in my step dads.)

The only way to really check this area for straigntness is with a known straightedge. I used a machinists straightedge to determine if its warped. Then the fun starts.

/ubbthreads/images/graemlins/cheers.gif

 

[trboost]

Re: Best way to fix the oil leak at front of block

I found part of the original service record: #151134 is the new improved crappy replacement.. Mine was a cronic leaker as well. on my last rebuild I paid special attention to this, made sure the Keensets were in, checked for fit & used the Halomar sealant. Now if the additional crankcase pressure of the blower doesn't make it leak , nothing will. It has been bone dry for over 30,000 miles.

June 5, 1969A new front sealing block, part number 151134, has been introduced to provide better crankcase sealing by eliminating the possibility of "bowing" during assembly. The new seal is clamped to the front engine plate by three set-screws instead of one as previously used and was incorporated from the following engine numbers:

Oil leakage from the sealing block of an entire engine prior to the above numbers can be rectified by fitting the new block as follows:

Remove the front engine plate and sealing block as described in the appropiate Workshop Manual.

Locating a new gasket (part number 215350) on the engine plate, carefully mark the positions and drill two additional 3/8" (9.5 mm.) diameter holes.

Using "Hylomar" jointing compound on both faces of the narrow strip gasket (part number 150531), assemble this to the crankcase, followed by the new sealing block 151134, which must be aligned with the front face of the cylinder block before final tightening.

Coat both faces of the new engine plate gasket (215350) with "Hylomar" jointing compound and attach this and the modified engine plate to the cylinder block.

Use two additional set-screws, PT.0805, and spring washers, WL.0208, when securing the engine plate.

New Parts:

Sealing Block - 151134
Strip Gasket - 150531
Engine Plate Gasket - 215350
2 Set-Screws - PT.0805
2 Spring Washers - WL.0208

 

[Guest]

Re: Best way to fix the oil leak at front of block

I installed the steel aftermarket front sealing block. It is very well made and fits perfectly. Using adequate sealants and proper torqueing sequence usually solves this problem handily.

Bill

 

[RobT]

Re: Best way to fix the oil leak at front of block

A couple of folks have suggested reinstalling the PCV valve, so I might give that a go before taking the motor apart. I have the "GoodParts" tipple ZS setup on my TR250 (which works very well BTW), and am wondering how to go about installing a PCV valve on it.

Currently the rocker cover vents into the air intake, and the vacuum for the brake booster comes of the manifold. Does anyone know do I need to install a "T" from the brake vacuum line and the PCV on that (with another "T" from the rocker cover to the air intake)? Seems like this might suck oily fumes into the brake booster. Or is there another way to run the PCV with the triple ZS setup?

Rob.

 

[Andy Blackley]

Re: Best way to fix the oil leak at front of block

Rob T: I asked that question in a similar thread concerning the Goode manifold back in October.
Here was the reply: "Andy, Yes. For an extra $30. Richard welded a different bung on the middle manifold that has two inline ports: one for the brake booster vacuum hose, the other for the PVC valve.

--------------------
Dave Arbour
'68 TR250 "

I am not sure what the difference is in having two closely spaced ports on the same manifold branch vs. a single one shared by the brake booster and the PCV. Maybe Richard Goode could provide an answer.

 

[gjh2007]

Re: Best way to fix the oil leak at front of block

Rob:

No problem mentioning me, I also concur with others that before I replaced the blocked off PCV (Gulp) valve on my 250 it leaked like a stuck pig bleeds from the valve cover & side of block. After installing the PCV valve 90% of my leaks have subsided. Much easier than pulling the front cover. /ubbthreads/images/graemlins/wink.gif

 

[Guest]

Re: Best way to fix the oil leak at front of block

Rob, I pulled the three vacumn lines on my Strombergs through GoodParts oil separator to reduce the pressure in my crank. Seems to work, no more than the usual and sundry oil leaks.

Bill

 

[DougF]

Re: Best way to fix the oil leak at front of block

As a sealant, I would highly recomment Permatex "Right Stuff" or "Good Stuff". I forget the Permatex brand name. Anyway, use this product without the paper gaskets and you should end all leak problems. You may still want to use your oil pan gasket in conjunction with it.
This is a rubber base type RTV available in either an aerosol or a caulk tube form. I sell this product under a different label and have had excellent results. It seals in the time it takes to strap things together. I've installed a thermostat and run the engine immediately without leaks.
One caution, it does not work around gasoline.