Oil Cooler lines

[332bill]

My recently acquired (3/13/04) 99 Suburban has leaking oil cooler lines. I have read the other threads here and intend to order new lines from Lube Specialists tomorrow. I don't think they are leaking a lot, just a bunch of drips hanging down. I don't see anything on the ground where I park it, but there is oil on the frame. In the mean-time, is there much risk of a leaking line bursting. Should I refrain from driving it much until I replace them? I was thinking of taking it on a short trip this weekend (200 miles).

thanks,
Bill

BTW, I really like my new truck.

[Shotuscnc]

i recently bought a similar suburban... and quickly upgraded the oil cooler lines... really got antsy when i started reading of catastrophic failures attributed to o/c lines... waste no time in replacing.. and remember that you will not have time to save the engine should the line burst..

good luck, I love my burb..

[Andy Chesek]

I recently had to replace the lines on my '99 pickup, so I'm qualified to chime in here.

The one line had a slight leak, much like yours, where oil was just getting things a little wet underneath. It was like that for about 2 months before it decided to become a serious problem. I drove to work one night (10 miles) and noticed a trail of oil in the parking garage that ended under my truck. Checked the dipstick, and I was down a good 2 quarts. Borrowed a co-worker's vehicle so I could run home and get some oil. Got back to my truck, topped it off and drove home... lost another 2 quarts in 10 miles.

If I were you, I would replace the lines before going anywhere. Who knows when that small drip will turn into a gush. Turbos and engines aren't cheap, either.

I've got a set of lines from Greg L. as well. I appreciate his quick service, and would recommend him just as many others on the page have.

[john8662]

Mine were leaking on my 95 for awhile, until I realized that the lines were the final thing leaking. Before that I had some leaks on the oil filter adaptor which made things oily. I replaced the lines on the burb just because I knew something was leaking and that I could get them replaced while I had the money and time. Once I got in there to replace it, I am glad that I did, because now I am drip free. These lines don't usually fail all-at-once. Usually just leak for a while and make a mess. But then again, some do fail quickly. I drove mine for quite some time, on long trips and things without a problem. The lines just seem to seep.

[gvig]

I just replaced the oil cooler lines on my truck. They had been weeping for about 6 months and I finally got tired of checking them and worrying about tramatic failure. I went to a local hose shop that has done work for me in the past. I had 1/2 inch i.d. SS braided lines made up. With fittings they cost me $140.06 My question is this, was my price reasonable?? Did I pay too much??

[CareyWeber]

Bill,

I have 172K miles on my 97 and the lines have dripped slightly since I good the truck at 43K miles.

Since about 170K the leaking has gotten worst so I'm going to get Greg's lines too.

The bad thing is if the go most likey you'll lose the engine.

Carey

Carey

[ttpost]

where do you find these dr. lee cooler lines thanks

[dstoops]

I had the oil lines replaced about 5 yrs ago with new GM parts. Everything is still "squeeky clean" at the engine but I'm seeing a little seepage at the cooler end under the radiator. It appears where the rubber line is "swedged" onto the aluminum end. I'm thinking that if I could "re-swedge" it with a clamp or something the seepage would stop...Has anybody tried anything like that?

[Diesel Dan]

George,
That doesn't sound like a bad price for braided lines. I replaced the lines on my '00. What I used was Parker Push-lok silicon hose. I have around $85 in hose and fittings. If I was too do it again I would use all 45* fittings(about$10 more) or hard pipe some lines up too the motor mounts. Gets kinda tight around the oil filter adapter on a 4wd. 2wd would be much easier or lifted trucks without the horizontal filter adapter.

[Diesel Dan]

BTW,
I have less than 12 months on factory GM cooler lines on our '99 s-blazer. One is starting to seep at the crimp. And as a former GM tech, they do fail without warning and can take the motor out.

[LanduytG]

The custom oil cooler lines are made from Parker hose and fittings. The older models (96) and yearlier are 1/2". 97 is a mix of 1/2" and 5/8" so you need to check to see what you have. 98 and newer are all 5/8". Line sets come complete with everything you need from the block to the cooler. 1/2" set is $115 and the 5/8" set is $125. Can't even begin to tell how any of the 1/2" sets I have sold. I have a hard time keeping them in stock.

Greg

[G. Gearloose]

Who knows what size o-rings are on the filter adapter?
I suspect reusing them would be futile; would like to have all the parts before disassembly.

[CareyWeber]

Originally posted by LanduytG:
The custom oil cooler lines are made from Parker hose and fittings. The older models (96) and yearlier are 1/2". 97 is a mix of 1/2" and 5/8" so you need to check to see what you have. 98 and newer are all 5/8". Line sets come complete with everything you need from the block to the cooler. 1/2" set is $115 and the 5/8" set is $125. Can't even begin to tell how any of the 1/2" sets I have sold. I have a hard time keeping them in stock.

Greg Greg,

Where is the best place to measure the OEM lines on a 97 to tell which size I need to order?

Carey

[JohnC]

Originally posted by G. Gearloose:
Who knows what size o-rings are on the filter adapter?
The GM part numbers are posted in the part numbers section of the DP.

[LanduytG]

Where is the best place to measure the OEM lines on a 97 to tell which size I need to order? You can do this one of two ways. Measure the OD of the metal part of the line or you can see what size wrench fits the oil cooler fitting. If the cooler fitting is 3/4" then its the half inch line set. If its about 1-1/16" you have the 5/8" line set. Most late model 97 are 5/8". Another thing to watch is the fitting size on the block. We have seen several early model 97's that have half inch lines (those come with a 3/8" NPT to 1/2" 90* fitting for the block}but have he 1/2" NPT thread in the block for the 5/8" lines. What you do in that case is you get a 1/2" to 3/8" NPT bushing.


Greg

Greg

[G. Gearloose]

The GM part numbers are posted in the part numbers section of the DP. Thank you for responding; but I am most interested in the sizes.

[332bill]

Thanks for all the replies. I cleaned the hoses off well and at this point they are just weeping at the crimps. But I did order the hoses from Lube Specialsts and will replace them as soon as they arrive. When I changed the oil Friday I looked around where the cooler lines connect to the engine and it does look a little tight in there. I have heard on the 4x4's its best to disconnect the front driveshaft to get easier access to the fittings. Any other tips? How about removal of the fittings at the cooler? Is it best to remove the grill?

Thanks,
Bill

[rjschoolcraft]

The only way to do it is to remove the grill. ;)

[Marty Lau]

When you remove the grill this is a good time to check and clean your A/C condensor and Raditor they tend to clolect stuff that hurts cooling between them. Also good time to look for Raditor leaks. (check lower corners of raditor)

[DickWells]

Hi G. Gearloose: The part numbers for the oil filter addapter seals are as follows.
12559095 copper washer
23500358 O-ring
23500360 O-ring 2 needed

This info is per Jim Bigley from several years ago. I seem to remember that one of these wasn't used in my adapter, but I don't know which one. It isn't important anyway, since they're not too costly.
He gave me a torque spec of 40 ft lbs for the big nut, and that's what I used, though it sounds a little light. I guess that big flat machined surface really grabs.
Hope this is of some help to you.
Dick