off-topic - '85 Chevy RV oil leak at oil filter adapter

[Randall K.]

Hi - more problems with my RV... built on a '85 Chevy P-30 chassis, 454 engine.

I'm seeing a significant oil leak that appears to be between the oil filter adapter and the block - as much as 2-3 drops per second at the highest pressure (~45 PSI at cold startup), and still around 1 drop per second after warming up and at idle (~20 PSI), using 10-30 oil. This engine also has an oil cooler with the inlet and outlet lines connected at the adapter.

Is there a seal that can be replaced between the oil filter adapter and the block? Is this a difficult repair?

Thanks in advance!

Randy Krohn (43621)

[Terry M.]

Re: off-topic - '85 Chevy RV oil leak at oil filter adapter

I am not familiar with that arrangement on the large motor, but my Caprice police cars with the Gen II LT1 have the adapter for oil cooler between the filter and engine case. There is a paper gasket between the adapter and cylinder case. and seals at the adapter to oil line(s) fitting(s). I would expect the same in your situation. Visit a Chevrolet dealer's parts department and have them bring up a picture of the adapter and lines for your application on their computer. That view will show if there are gaskets or O-rings or seals in the area. It won't be the least expensive way out, but buy or order what you need from them. If you ask politely they may print the vies so you can see what you have to remove to change the gasket.

I can tell you in my case getting the old paper gasket out of the cylinder case was not so easy. It had hardened into a solid mass, and access to the area with adjacent catalytic convertor was difficult. You MUST remove ALL the old gasket material. The new gasket was a silver metallic material. I suspect they changed from the production piece for greater sealing effect.

[Randall K.]

Re: off-topic - '85 Chevy RV oil leak at oil filter adapter

Terry - thanks for the info. For what it's worth, the AIM for my '72 454 shows one bolt holding the oil filter adapter into the block. Is this typical? My bad - I should have taken a picture when I pulled the filter over the weekend, but just really didn't think about it.

Randy

[Joe L.]

Re: off-topic - '85 Chevy RV oil leak at oil filter adapter

Terry - thanks for the info. For what it's worth, the AIM for my '72 454 shows one bolt holding the oil filter adapter into the block. Is this typical? My bad - I should have taken a picture when I pulled the filter over the weekend, but just really didn't think about it.

Randy

Randy-----


If you're talking about a 1972 Corvette with 454, there are TWO bolts which retain the oil filter adapter to the block (although the AIM may only show one of them). There is no gasket between the block and the adapter.

As far as the 85 motorhome, I'm much less familiar with the oil cooler set-up. If you have the style with an adapter that "sandwiches" between the block and the filter AND the filter is VERTICALLY INSTALLED, then I THINK you use adapter GM #12559732. With this set-up there is a gasket and seal used ABOVE the adapter but no gasket or seal used below that (except, of course, the seal on the oil filter). I believe a single bolt retains the adapter to the block.

I believe the GASKET was GM #14102025 and later GM #12551589. However, the latter is discontinued and I can't find a new number although there may be one. I THINK the SEAL is GM #10244495 and it's still available.

Like I say, I'm not sure of any of the above. Let us all know how it turns out.

[Terry M.]

Re: off-topic - '85 Chevy RV oil leak at oil filter adapter

I would not draw any conclusion regarding your motor home based on a 1972 Corvette AIM -- that is a case of apples and oranges. Tape a print-out of Joe's message with the part numbers included therein and go to your favorite Chevrolet parts department. See what you need and get it.

As Jae says the oil filter adapter on a 1972 BB has two bolts holding it on -- So does my Gen II LT1 fot the oil cooler adapter, but neither tells us much about your motor home. A close examination of the adapter when you had the oil filter off would have been definitive, however a trip to the Chevrolet dealer would still be in order.

[Clem Z.]

Re: off-topic - '85 Chevy RV oil leak at oil filter adapter

I would not draw any conclusion regarding your motor home based on a 1972 Corvette AIM -- that is a case of apples and oranges. Tape a print-out of Joe's message with the part numbers included therein and go to your favorite Chevrolet parts department. See what you need and get it.

As Jae says the oil filter adapter on a 1972 BB has two bolts holding it on -- So does my Gen II LT1 fot the oil cooler adapter, but neither tells us much about your motor home. A close examination of the adapter when you had the oil filter off would have been definitive, however a trip to the Chevrolet dealer would still be in order.

there is a "O" ring that seals the adapter to the block,same place as the "O" ring on the oil filter. take off the oil filter and check the bolts holding the adapter to the block to make sure they are tight

[Joe L.]

Re: off-topic - '85 Chevy RV oil leak at oil filter adapter

Terry - thanks for the info. For what it's worth, the AIM for my '72 454 shows one bolt holding the oil filter adapter into the block. Is this typical? My bad - I should have taken a picture when I pulled the filter over the weekend, but just really didn't think about it.

Randy

Randy-----


Also, you can obtain a Fel-Pro manufactured seal kit for your application which contains all the gaskets and seals you need, plus a few you probably don't need. It's Fel-Pro #ES72671 and it costs less than 10 bucks.

[Jim T.]

Re: off-topic - '85 Chevy RV oil leak at oil filter adapter

My 85 Corvette has the heavy duty cooling and has the oil cooler between the block and the spin on filter.
The gasket between the oil cooler and the block in 1993 purchased from GM was expensive for just one gasket.

[Terry M.]

Re: off-topic - '85 Chevy RV oil leak at oil filter adapter

I generally prefer to get my parts from Chevrolet when I can for several reasons:
1) I have more assurance they are the parts I want and they will fit the application.

2) The quality of the part is sometimes (but I know not always) superior to the part available in the aftermarket. I do know, however, that sometimes the Chevrolet part is produced by the same source as the aftermarket part.

3) If the part is at all difficult to change, I prefer the assurance that the part I am buying from Chevrolet will last longer than the aftermarket part.

I dislike going to the FLAPS and have some pimply faced kid ask me for the VIN number of my car when all I need is some generic part. Most of my cars are older than the "Associates" at these stores, and I sometimes think the managers of these stores go out of their way to hire people who know nothing about automobiles. If it is not in their computer -- they are lost.

I have a relationship with the folks where I get my parts. One of them has been selling me parts since my 1970 was new.

[Joe L.]

Re: off-topic - '85 Chevy RV oil leak at oil filter adapter

I generally prefer to get my parts from Chevrolet when I can for several reasons:
1) I have more assurance they are the parts I want and they will fit the application.

2) The quality of the part is sometimes (but I know not always) superior to the part available in the aftermarket. I do know, however, that sometimes the Chevrolet part is produced by the same source as the aftermarket part.

3) If the part is at all difficult to change, I prefer the assurance that the part I am buying from Chevrolet will last longer than the aftermarket part.

I dislike going to the FLAPS and have some pimply faced kid ask me for the VIN number of my car when all I need is some generic part. Most of my cars are older than the "Associates" at these stores, and I sometimes think the managers of these stores go out of their way to hire people who know nothing about automobiles. If it is not in their computer -- they are lost.

I have a relationship with the folks where I get my parts. One of them has been selling me parts since my 1970 was new.

Terry----


Yes, I agree and usually prefer the GM parts myself. However, in this case, it appears that the gasket is GM-discontinued (unless there is a new number that I have not been able to come up with but which the GM dealer should be able to determine). If there is no new part number then all he'll be able to get is the seal at GM. He likely won't be able to purchase just the gasket separately at an auto parts store, so that means he'll have to get the kit anyway. Then, he'll have 2 seals which is one more than he needs.

As far as gaskets go, I don't think that GM ever made any in-house. They were and are supplied by the major gasket manufacturers. In the "old days" a lot of GM gaskets were made by Detroit Gasket and, in those days, Detroit Gasket did not supply gaskets to the aftermarket. So, if one wanted an OEM quality gasket, you had to get it from GM. Detroit Gasket (now known as Corteco) has supplied gaskets to the aftermarket for quite a few years, so if one wants those you don't need to get them from GM.

Now the question arises do the major gasket manufacturers offer the same gaskets they make for the OEM market in the aftermarket. In other words and for example, if you purchase, say, a Victor-Reinz gasket set for a small block Chevrolet intake is it the same exact set as they supply to GM for PRODUCTION and SERVICE? The answer is sometimes yes and sometimes no.

[Joe L.]

Re: off-topic - '85 Chevy RV oil leak at oil filter adapter

My 85 Corvette has the heavy duty cooling and has the oil cooler between the block and the spin on filter.
The gasket between the oil cooler and the block in 1993 purchased from GM was expensive for just one gasket.

Jim----


It still is. That gasket is GM #14087586 and it currently GM lists for about 24 bucks for just ONE gasket.

[Clem Z.]

Re: off-topic - '85 Chevy RV oil leak at oil filter adapter

there is a gasket that goes against the block at the top of the adapter that seals the input of the oil from the oil pump from the oil returning to the oil gallery after going thru the filter and the oil cooler. there is a "O" ring that seals the adapter to the block just like where the oil filter gasket seals.

[Terry M.]

Re: off-topic - '85 Chevy RV oil leak at oil filter adapter

Joe, I was not specifically referring to gaskets in my last post. In this case there appears to be little choice, and Victor used to make good products.

Just as an aside: In the '70s I had access to one of their plants during my day job. We supplied them power. The door I went through rained asbestos onto me. Those were the days. Last time I was at that location they were making movies there.

I still look for those gaskets with GM stamped on them though.

[Randall K.]

Re: off-topic - '85 Chevy RV oil leak at oil filter adapter

Thank you to all who chimed in. The local Chevy dealer looked up the details for the '85 P-30 454, and no gasket is shown - just the o-ring seal, which will cost me a whole whopping $3. I'll be taking this apart Friday night - and hoping I don't find the remnants of a gasket...

Randy

[Randall K.]

Re: off-topic - '85 Chevy RV oil leak at oil filter adapter

All - sourced both the GM gasket and the FelPro kit ($10 at AutoZone) - turns out that this system does use a gasket as well as the o-ring. As noted, the gasket was mostly hardened, and required quite a bit of scraping. The most curious part was the condition of what used to be the o-ring. It had turned into a hard, blackened, flaky mass that seems to have extruded itself onto the inner surfaces of the oil filter adapter. This can't be what GM had in mind for this material...

Good news is - leak fixed! And, since I had lots of stuff out of the way, fixed a small exhaust leak with a new gasket where the pipe joins the exhaust manifold.

Thanks again to all for your support.

Randy