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Fixing front crank oil seal for good


jevansio

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I've blown the front crank oil seal out again and I'm going to fix it once & for all, couple of questions on the subject.

 

1. Planning on getting one of PHR's modified oil pumps from Joe. Anyone any experience of these? Anyone used one on an engine that kept blowing seals before & it stopped after?

 

2. I hear there is a modified seal too (the spring is replaced), anyone got comments on this.

 

3. My crankcase breathers just vent to atmosphere, I'm planning on routing these into a catch tank, then back into the intake. Will this help?

 

4. What oil pressure do you guys see? I get 6 BAR on idle when cold, dropping to around 3 when fully warm. When on WOT I get as high as 7 BAR.

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I've blown the front crank oil seal out again and I'm going to fix it once & for all, couple of questions on the subject.

 

1. Planning on getting one of PHR's modified oil pumps from Joe. Anyone any experience of these? Anyone used one on an engine that kept blowing seals before & it stopped after?

 

Yes i have fitted one they are basically a std pump with the seal drain channel opened up a bit, its quite easy to modify a std pump yourself;)

 

2. I hear there is a modified seal too (the spring is replaced), anyone got comments on this.

 

The modded seal IMO is not worth the bother, it can cause premature wear to the crank!

 

3. My crankcase breathers just vent to atmosphere, I'm planning on routing these into a catch tank, then back into the intake. Will this help?

 

Crankcase breathing is pretty much irrelevant to crank seal failure, unless you are running a stroker or very high boost pressure, and then you really need to use larger breather outlets.

 

4. What oil pressure do you guys see? I get 6 BAR on idle when cold, dropping to around 3 when fully warm. When on WOT I get as high as 7 BAR.

 

Oils pressure is also pretty irrelevant, as 99% of seal failures are down to a worn oil pump, caused by particle damage, or fuel contaminated oil.

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Did you get it sorted in the end then? Good to know it's fixable, I've had about 3 in now :)

 

Fitted a larger seal in the end from the states, my mate that lives in Canada sourced it for me, i did have a spare but not sure where it is since i moved, ill have a look for it mate, but tbh im not sure they are needed, proper fitting in a new pump should do the trick.

 

Edit... did you have a new pump fitted with the rebuild?

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Oils pressure is also pretty irrelevant, as 99% of seal failures are down to a worn oil pump, caused by particle damage, or fuel contaminated oil.

Many thanks for all those answers Ricky, I'm not really upto modifying a pump myself, I think I'll go with a new PHR pump & standard seal.

 

Fitted a larger seal in the end from the states, my mate that lives in Canada sourced it for me, i did have a spare but not sure where it is since i moved, ill have a look for it mate, but tbh im not sure they are needed, proper fitting in a new pump should do the trick.

 

Edit... did you have a new pump fitted with the rebuild?

Many thanks for the offer Jamie, like you say I reckon a new pump should do it so don't go wasting your time on it :)

 

Will have to check with Michel, I thought so.

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Many thanks for all those answers Ricky, I'm not really upto modifying a pump myself, I think I'll go with a new PHR pump & standard seal.

 

 

Many thanks for the offer Jamie, like you say I reckon a new pump should do it so don't go wasting your time on it :)

 

Will have to check with Michel, I thought so.

 

I should add that the pump that is removed should be carefully examined to see the existent of the wear, as if servier, then it would be advisable to do a complete engine rebuild.

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i had a nightmare with mine through people not fitting it properly.

 

Was that the case in the end ?

 

Did TF do all of them for you ? I came to this conclusion reading inbetween the lines that it was down to poor fitting...no disrespect to you Jamie ;) and have read of other traders installs where this has happened too :( OK, just one recently on this board.

 

I'm ~1200miles into my CW rebuild using the later style Toyota Oil pump and it's holding up well so far.

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3. My crankcase breathers just vent to atmosphere, I'm planning on routing these into a catch tank, then back into the intake. Will this help?

 

Just to add - this is definately a good thing to do - whether it helps this issue or not.

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Jay, are you using one or two cam breathers? I have fitted two -12 lines (not tee'd) direct to a baffled catch can, from there, I used a 22mm line to the intake.

To create a little vacuum, fit a slash cut tube facing the compressor.

I've got two enlarged cam breathers, thanks for the tip too :)

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Was that the case in the end ?

 

Did TF do all of them for you ? I came to this conclusion reading inbetween the lines that it was down to poor fitting...no disrespect to you Jamie ;) and have read of other traders installs where this has happened too :( OK, just one recently on this board.

 

I'm ~1200miles into my CW rebuild using the old style Toyota Oil pump and it's holding up well so far.

 

TBH i dont really know mate but it was a nightmare, i got through about 6 FMS in the end, wish id just shipped the car up to CW and been done with it.:)

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Jay, are you using one or two cam breathers? I have fitted two -12 lines (not tee'd) direct to a baffled catch can, from there, I used a 22mm line to the intake.

To create a little vacuum, fit a slash cut tube facing the compressor.

 

at what point do you need to start looking at breathers is it power or boost related ?

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at what point do you need to start looking at breathers is it power or boost related ?

 

You need to start looking at breathers when blowby gets excessive. Since noone measures crankcase pressure when tuning (even though its pretty easy to do) you will only start to suspect that you are suffering from blowby when you see some symptoms like excessive oil carry over (possibly leading to detonation), popping shaft seals, oil dilution, etc.

 

Blowby is a % of the mixture in the cylinder that gets past the piston rings on the compression, power and exhaust strokes. Typically, if you stuff more air into the cylinder you will get more blowby, so if you raise boost pressure you can expect an increase. However, piston rings tend to seal better under increased load, so up to a point you will get better ring sealing on the combustion stroke on a more powerful engine. If you raise the rev limit (even by a little bit) you may cross the line where the ring pack starts to "flutter", which can seriously impair its sealing capability - leading to a big increase in blowby.

 

Ideally its better to fix the problem rather than the symptom. i.e. fix the piston rings rather than putting a band aid over the problem by modding the breather system to cope with the extra volume of blowby gas, but if you must mod the breather system then the propoer way to do it would be to measure the crankcase pressure via a tube connected to the dipstick or (my preference) the oil filler cap. Ideally you should see a crankcase depression of 20-200mbar across the whole operating range. Under very low speed / low load you might see the preddure approach atmospeheric. Once you are out of the idle condition, if you see any significant positive crankcase pressure then its time to start thinking about sorting the breather system out (or fixing the blowby problem at its root cause).

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at what point do you need to start looking at breathers is it power or boost related ?

 

Not sure tbh Paul, I have'nt had a seal problem but upgraded the breather system when I increased my rev limit to 7500. (which its constantly bouncing off and showing 7700 on the avcr)

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It's nothing to do with venting to atmo, you don't need or probably want a "modified" oil pump, just a stock one. The cause is pump wear, and the cause of that is either oil dilution if the engine has had the fuelling delivery modded, or *rap in the engine when it was built, stripped or generally *uggered about with. As such it would only be a proper job if the engine was fully stripped and cleaned, and rebuilt checking all other oil lubed moving parts for wear and damage. Half baked repairs have short lives with this problem. the fix is dead easy, the time and cost is high. All talk of boost, crank walk, faulty batches of pumps, blah blah is total bull. My engines don't blow front seals when fixed properly :) talk of changing oil pumps in situ make me cringe, it's EXACTLY such attempts that fill the engine wih muck that CAUSE such problems in the first place. You have a car that probably cost the equivalent of 50K new, invasive engine repairs on complex twin turbo 6 pot lumps aren't cheap I'm afraid.

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