Oil filter adapter leak at engine

1992 S10 Blazer, TBI, 4x4

I recently developed a small leak from the oil filter adapter at the engine. I bought the Dorman 82560 (http://www.dormanproducts.com/itemdetail.aspx?ProductID=24849&SEName=82560) kit from O'Reilly's. The kit I received had two large o-rings that could fit the adapter. I used the tan one first and it leaked. I switched the black one, which seems a bit smaller, and it still leaks. I torqued to specs and this didn't work out, so I tightened by hand until I felt it was far enough. It is still leaking oil. But it doesn't really leak until I am stopped with the engine off. I thought maybe I damaged the surface when cleaning the old gasket off, but it looks fine. One thing I noticed is that the rear bolt feels like it doesn't want to tighten like the front bolt. So, I am thinking the threads are damaged and may need to be re-threaded.

Any other suggestions? Anyone ever have to re-thread the bolt hole for the adapter? Seems like it would be a pain.

Regarding the bolt size. This is what I found off a parts website: HFH, 5/16-18x3.25, .94 THD, 280M, PZOR(8.913)
I know that 5/16-18x3.25 is the bolt size, but what do all the other numbers and letters mean? Would it be possible to get a slightly longer bolt to grab at unused threads to save this project??

bring the bolt to auto store like advance auto. they have bolts. match up with what you need. measure the bore and see if you can find one at the store longer that will fit.

using a solvent spray straw blow out the threaded bore before installing the stud. this should reduce slippage..

cleaning the O ring surface is needed. the O ring could be too big and not seal correctly. big in the thickness not the diameter . the O rig needs some room to compress.

I would replace both studs and torque each stud equally. slowly until at about 20 ft lbs.

I'm going to try that today. I'll buy a couple different bolts in different lengths. Then measure the bore length and see if I can use a different bolt length.
I know the o-ring has room to compress. It was obvious when installed.
I'm mainly worried the threading is messed up. I may have to re-thread, which could be difficult.

I'm going to try that today. I'll buy a couple different bolts in different lengths. Then measure the bore length and see if I can use a different bolt length.
I know the o-ring has room to compress. It was obvious when installed.
I'm mainly worried the threading is messed up. I may have to re-thread, which could be difficult.

why do you think the treads are damaged ? is the stud with damaged threads ?

why do you think the treads are damaged ? is the stud with damaged threads ?


Because I've gone way past the torque specs and it won't tighten correctly. The front bolt is just fine. There's been some work on this truck that I didn't do, so wouldn't put it past a mechanic tightening too much. I'm a torque spec guy, and I know many people are tighten-it-down types.

Engine is cooling. Hope I can get to it before work.

Well, all the bolts I bought were not right. The threading is just slightly different even though they are both 5/16-18. They match up for about half an inch then they are off. The new ones wouldn't even go in the bore. So, I "tap/died" the original bolts and bores to clean them out. I reinstalled and slowly torqued to 20 ft/lbs, switching off every 1 ft/lb from 15 to 20. It leaked again. So, I torqued to 25 ft/lbs and then I had to drive to work. When I arrived, it didn't leak, but I'm sure there will be a nice puddle when I leave work tonight.

Question about the gasket. The "D" gasket that came with the kit is a metal gasket with thin paper on both sides. Having done this job a couple times before due crap failing oil lines, I usually get a paper gasket. Why a metal gasket? And should the thin paper come off? I looked at it and it didn't seem like it should come off, so I didn't, especially since I normally have a paper gasket to begin with. Your thoughts?

Well, all the bolts I bought were not right. The threading is just slightly different even though they are both 5/16-18. They match up for about half an inch then they are off. The new ones wouldn't even go in the bore. So, I "tap/died" the original bolts and bores to clean them out. I reinstalled and slowly torqued to 20 ft/lbs, switching off every 1 ft/lb from 15 to 20. It leaked again. So, I torqued to 25 ft/lbs and then I had to drive to work. When I arrived, it didn't leak, but I'm sure there will be a nice puddle when I leave work tonight.

Question about the gasket. The "D" gasket that came with the kit is a metal gasket with thin paper on both sides. Having done this job a couple times before due crap failing oil lines, I usually get a paper gasket. Why a metal gasket? And should the thin paper come off? I looked at it and it didn't seem like it should come off, so I didn't, especially since I normally have a paper gasket to begin with. Your thoughts?
An 8mm bolt is very close to a 5/16 this would explain the slightly different threads.

An 8mm bolt is very close to a 5/16 this would explain the slightly different threads.

Well, the specification in the parts book for these bolts is 5/16 (http://www.gmpartswiki.com/getpage?pageid=109145), and the tap and die I used to clean the threads was 5/16. I guess the pitch of the threading was different on the new bolts or the stock bolts are not standard.

I got out of work tonight and no leak, so here's hoping I actually fixed the leak and can move on to the thermostat issue.

Again, does anyone know if the metal gasket is the new standard and should the paper be removed??

Well, the specification in the parts book for these bolts is 5/16 (http://www.gmpartswiki.com/getpage?pageid=109145), and the tap and die I used to clean the threads was 5/16. I guess the pitch of the threading was different on the new bolts or the stock bolts are not standard.

I got out of work tonight and no leak, so here's hoping I actually fixed the leak and can move on to the thermostat issue.

Again, does anyone know if the metal gasket is the new standard and should the paper be removed??
I think these are special GM bolts as they are listed in a special size. Email
techsupport@dormanproducts.com You are using their adapter.

Well, the bolts really looked in good condition, so maybe I don't need to worry about them. If I have to, I know I can order them online.

Funny thing, I have emailed Dorman, twice. First to ask exactly which large o-ring to use, because there are two very close to the same size. They side to just match what came off the car. Then I emailed about the gaskets. They emailed back telling me the kit comes with two paper gaskets. Completely wrong. From the specifications tab on their website:
Gasket Material: Rubber and Steel
Package Contents: 13 O-Rings, 2 Metal Seals

I sure hate companies that don't know their products.

Well, the bolts really looked in good condition, so maybe I don't need to worry about them. If I have to, I know I can order them online.

Funny thing, I have emailed Dorman, twice. First to ask exactly which large o-ring to use, because there are two very close to the same size. They side to just match what came off the car. Then I emailed about the gaskets. They emailed back telling me the kit comes with two paper gaskets. Completely wrong. From the specifications tab on their website:
Gasket Material: Rubber and Steel
Package Contents: 13 O-Rings, 2 Metal Seals

I sure hate companies that don't know their products.

the leak you have is common in this area. the surface need be cleaned and smooth to stop oil from leaking the paper material on the steel is to provide a good seal on each side but the surface need be smooth and very clean.

I did say to bring the bolt to the store. when you stated 5/16 I thought that was weird. the head on the bolt if metric should have a marking on it.

I did say to bring the bolt to the store.

I would have loved to, but I have to drive the same car to the store.

I'm agreeing with rhandwor that the bolts are special. The specs say 5/16 and the die I used to clean it was 5/16, but if the pitch is different, they won't match up.

At this point, I have to check again this morning, but I believe the leaking stopped after I torqued it to 25 ft/lbs. So we'll see.

I would have loved to, but I have to drive the same car to the store.

I'm agreeing with rhandwor that the bolts are special. The specs say 5/16 and the die I used to clean it was 5/16, but if the pitch is different, they won't match up.

At this point, I have to check again this morning, but I believe the leaking stopped after I torqued it to 25 ft/lbs. So we'll see.

I would guess the OEM studs were metric.

(http://www.gmpartswiki.com/getpage?pageid=109145)

See listing.

See listing.

the parts diagram does show the 5/16-18 stud. perhaps some one used the metric studs and this is why it did not hold/leaked..

with the engines GM uses both types of studs this is why these mistakes are made...

So it turns out the gasket/o-ring kit from Dorman just doesn't work. I bought a Felpro set and did some measuring and with the specs from the Dorman kit, it's plain to see that it would never work. The steel gasket is too thick and the o-ring too thin. I put the Felpro kit on and torqued to spec and success. Felpro from now on. It also only comes with what you need, not multiple o-rings that are close to the same size to confuse you. Luckily the store took back the Dorman.

So it turns out the gasket/o-ring kit from Dorman just doesn't work. I bought a Felpro set and did some measuring and with the specs from the Dorman kit, it's plain to see that it would never work. The steel gasket is too thick and the o-ring too thin. I put the Felpro kit on and torqued to spec and success. Felpro from now on. It also only comes with what you need, not multiple o-rings that are close to the same size to confuse you. Luckily the store took back the Dorman.
I'm glad you got it fixed. You had a rough time.

Thanks. Of course, the lesson here is to stay away from Dorman when possible.

Thanks. Of course, the lesson here is to stay away from Dorman when possible.

these things can happen with the Chinese crap being made. the store took care of it and with your feed back, this will help others , with these leak issues in this area.. I stated before that many had problems with the repair of these leaks.