Oil Pump Leaking - Post TB Service?

[neoworm]

 

[neoworm]

That's the kind of room you are dealing with once the diff is gone. It's a lot.

 

[2001LC]

Looking at @SilverHundo picture in post #8. That is the worst oil pump O-ring leak I've seen. To see fresh oil make such a clear trial is; either a "salt job" or a very bad leak. I would've expected to see a lot oil and muck around the O-ring area. But knowing a timing belt service just done. Mechanic must have done a good cleaning job, during the T-belt service. For the leak to have gotten so much worst after the T-belt service. I suspect the engine had poor oil change history with cheap oil before now, and or HM oil was used previously. I'd be very interested in the oil service history?

I'm in the camp to first use a good rubber plasticizer, like AT-205. To see if weeps & leak can be managed. But this leak looks so bad. IMHO, will need O-ring replaced.

IMHO: Oil pump O-ring leak, is due to:
1) Shrinkage in rubber as the plasticize leaches out over time, sped up by heating and cooling. Cheap oil with long intervals between changes, speed up even more.
2) Use of HM (high mileage) oil. Which is a petroleum based seal modifier. This swells seal temporarily excessively. Mobil 1 states: If HM oil used for two changes or more, it must than be used for life of engine. If one stop using, then most if not all rubber seal will leak. These leaks, can get very bad. Which this one is!

I've been in the camp of not preemptively using oil additives:
BUT, I'm seeing more and more weeps as fleet ages.

I am now (more & more) recommending AT-205 be added to engines, gear boxes and PS.
First it was in power steering.
Than rear diff to reduce rear axle seal leak occurrence, saving bearing replacement service.
But the more T-belt service I do. The more I've noticed the O-ring weeps getting worst. AT-205 will not help weeps at FIPG seals or damaged rubber seals. But will help slow or stop all good rubber seal weeps. It used only once every 7 to 10 years.

To pull engine or not:
All 100 series FSM hard copy I have and online at TIS, do recommend pulling engine. The online manual posted in this thread, pictures look like engine out. It may just be that some online only give the oil pump, not the whole section (EM, lubrication) it comes from.

I do feel, we're least likely to get a pan leak afterwards, when engine on stand. But we've seen a number pull oil pans engine in, here in mud.

Will be interesting to see which method this shop does. Any bets?

 

[abuck99]

It's been awhile since I did it but I'm pretty sure I left the knuckles in place. IIRC I just removed the c-clips and slid the axles out the back as I removed the diff. Yes I removed the rear xmember.

I've removed a few engines and taking out the front diff to replace the oil pan certainly seemed like a lot less hassle to me. I'm pretty sure the only reason Toyota specifies removing the engine is to make reinstalling the pans easier. With the engine out you can turn it upside down and get the surfaces oil free and really make sure the pans are sealed well.

with the engine in you've got oil running down the inside of the block and you are working upside down over your head and possibly on your back. Higher chance you won't get a good seal on the pan.

HOWEVER, it is possible you just need to be patient and check everything 5 times. It really helped to have a second set of eyes and hands when I did it.

Cheers Thanks-

 

[JunkCrzr89]

Than rear diff to reduce rear axle seal leak occurrence, saving bearing replacement service.

Unrelated to the oil pump topic of this thread but I caution against this. Rear axle seal leaks on the Toyota semi-float axle design are often caused by bearing wear and are an indicator that the bearing needs replaced. There are of course other potential causes (e.g., clogged diff breather), but the semi-float design lends itself to rear wheel bearing wear that causes inner axle seal failure. IIRC, the FSM specs the rear wheel bearings as non-reusable in the event of inner axle seal failure.

 

[2001LC]

Unrelated to the oil pump topic of this thread but I caution against this. Rear axle seal leaks on the Toyota semi-float axle design are often caused by bearing wear and are an indicator that the bearing needs replaced. There are of course other potential causes (e.g., clogged diff breather), but the semi-float design lends itself to rear wheel bearing wear that causes inner axle seal failure. IIRC, the FSM specs the rear wheel bearings as non-reusable in the event of inner axle seal failure.

Whereas, I agree bearing failure will result in seal damage (failure). I would also agree seeing the leak, may indeed indicate a bearing failure. I would also agree if seal leaking, it best is to replace seal & bearing regardless of which failed first

I would argue rear axle seal failure is a leading cause of bearing failure. In that gear lube enters the normally dry cavity between the inner seal and factory sealed bearing. The gear lube in time, will then enter through bearings seal. The gear lube contaminates bearing grease, which result in bearing failure.

So I seen no harm adding AT-205 preemptively. It will only revitalize seal and buy time. How much time is hard to say. But at least, bearing failure will be less likely due to contamination of its grease. Provided seal has is not damged before adding and breather working properly. If seal is leaking already, "well", start saving for a axle bearing service.

 

[SilverHundo]

Well the guys at the shop did some more research, called some contacts at Lexus, and did end up sending me a quote for the front diff / oil pan repair route.

Quoted me $1,563 so I told them to go for it. I don't have the time right now to DIY. Way better than pulling the engine..but still a hell of an invoice for one little O-Ring.

He did say the Lexus guys told him that they've been seeing more and more of these oil pump leaks in the 4.7L motors and some of the Lexus LS models with similar oil pump configurations.

 

[Mike NXP]

Well the guys at the shop did some more research, called some contacts at Lexus, and did end up sending me a quote for the front diff / oil pan repair route.

Quoted me $1,563 so I told them to go for it. I don't have the time right now to DIY. Way better than pulling the engine..but still a hell of an invoice for one little O-Ring.

He did say the Lexus guys told him that they've been seeing more and more of these oil pump leaks in the 4.7L motors and some of the Lexus LS models with similar oil pump configurations.

Bummmer, It's OK you'll make more money and now the 100 series is ready to rally for more years to come.

 

[OregonLC]

Honestly, $1,600 for a dealer repair like that seems like a bargain.

 

[SilverHundo]

Honestly, $1,600 for a dealer repair like that seems like a bargain.

Not a dealer. But a good, honest local shop that specializes in Toyota/Lexus.

 

[OregonLC]

Still, figure $125 shop rate and that's only 10 or so hours (allowing for parts and fluids). Seems very reasonable for the work involved.

Again, I'd want a new belt tensioner on the re-install rather than compressing the one that was just installed. They can be damaged if the compression is not done correctly. Also, don't re-use the water pump gasket or any of the o-rings. Even though they were just installed, replace with new. I might even suggest new water pump bolts because the new ones that came with the kit have already been torqued once, but that may be overkill.

 

[2001LC]

He did say the Lexus guys told him that they've been seeing more and more of these oil pump leaks in the 4.7L motors and some of the Lexus LS models with similar oil pump configurations.

I agree, as I'm seeing increased weepage. This is why I've begun recommended a good plasticizer be used preemptively.

Notes:

• Plasticizer can NOT be used in brake systems.
• Some are saying the AT-205 has been reformulated, and that it's not working as well as it did pre 2020.

 

[jerryb]

I preached about that Oring in the past. It's probably the hardest, most dried out seal I've ever seen on a car.
1500 for a redo labor wise seems to me to be a great deal.

I'm not impressed with that factory seal job on it or the grooves themselves on that plate. Bad thing though, if the front is bad then the rear o ring is in the same condition.

 

[PNIT5000]

I'm battling oil pump leak perhas, mechanic saw the same type of oil trail from one of the upper oil pan bolts.

How did this work out for you? I mean did it work?

 

[SilverHundo]

I'm battling oil pump leak perhas, mechanic saw the same type of oil trail from one of the upper oil pan bolts.

How did this work out for you? I mean did it work?

Yes I had the shop drop the front diff, remove oil pan and they were able to access it that way, leaving the engine in the truck. It cost me $1,280 but it did solve the oil leak.

 

[PNIT5000]

Thanks, I might be looking at doing the same. @patchagan has a DIY video for the brave of heart. If you were ever going to regear or do a front locker, or even replace the CV axles and flange this would be a good time to do it. I’m guessing the prior owner of my well loved Hundy must have been using high mileage oil because once I started full synthetic it’s been pissing oil

 

[SilverHundo]

Thanks, I might be looking at doing the same. @patchagan has a DIY video for the brave of heart. If you were ever going to regear or do a front locker, or even replace the CV axles and flange this would be a good time to do it. I’m guessing the prior owner of my well loved Hundy must have been using high mileage oil because once I started full synthetic it’s been pissing oil

Yep they went ahead and did the CV axles also while they were at it. No labor.

 

[cruiserpatch]

Thanks, I might be looking at doing the same. @patchagan has a DIY video for the brave of heart. If you were ever going to regear or do a front locker, or even replace the CV axles and flange this would be a good time to do it. I’m guessing the prior owner of my well loved Hundy must have been using high mileage oil because once I started full synthetic it’s been pissing oil

When I removed the o-ring it was hard as a rock. It cracked with an audible *snap* when i pulled it off of the block.

Since replacing it, I have had zero issues. No oil leaks, oil pump still working as it was. Some recommended I replace the pump but I didn’t see why I should if it still worked

All that work for a $2 rubber o-ring

Another interesting thing that happened: I was unable to fit my old timing belt back on. It shrank so I had to buy a new one, just the belt, from my local dealer

Video:

 

[PNIT5000]

I’m thinking of tackling this, but also have a leak at the rear main seal. Maybe it’s better to just pull the engine at that point to do both?

 

[abuck99]

When I removed the o-ring it was hard as a rock. It cracked with an audible *snap* when i pulled it off of the block.

Since replacing it, I have had zero issues. No oil leaks, oil pump still working as it was. Some recommended I replace the pump but I didn’t see why I should if it still worked

All that work for a $2 rubber o-ring

Another interesting thing that happened: I was unable to fit my old timing belt back on. It shrank so I had to buy a new one, just the belt, from my local dealer

Video:

Thanks for the video ride-along of that job- which didn’t look fun- Looking back on the job- would you do it the same way again or pull the motor?