Has anyone else run into this problem? If so, how did you resove it?

Common problem. Replace. Duh.

Yea, tons of posts on here about that issue. Hoses leak at the connectors. You need to buy some new form fitted hoses, most auto parts stores have em, very common problem.

Yea, tons of posts on here about that issue. Hoses leak at the connectors. You need to buy some new form fitted hoses, most auto parts stores have em, very common problem.


A local mechanic quoted me $300.00 for the job. I have tried ordering the parts at a parts store. They tell me they aren't available due to the "pressure" fittings on the hoses. What are "form fitted" hoses?

The oil lines are pretty much a dealer item only... Gasket kit though can be bought for about 2 bux at advance autoparts though... The hoses going from to the rad from the remote oil filter are about 40 bux at the dealer, and the ones going to the engine are about 60.00. You can do the change yourself, pretty easy..

no no no people. This is a common problem I just replaced mine. Don't go to the dealer this is a simple job maybe takes an hour to finish. The part you need is made by dorman. The two part numbers are 625-100 and 625-001 depending on which set your replacing. most likely it will be the 625-100. if you do a google for "dorman oil cooler lines" you can see what I'm talking about. I went to my local carquest auto parts store and got them for around 30 bucks. I'm telling you seriously go get them you'll save time and money.

I had just found a 95 Blazer with this problem. The lady thought her engine was blown so I offered her $500 cash and took it home to find a leaky line.

Hope its this line and not a $1700 motor.

looks like its time for a new engine. I replaced the oil cooler line and leaks stopped so now it's time to replace this engine. Anyone need spare 4.3 parts looks like im gonna have some extras when I put my new one in.

no no no people. This is a common problem I just replaced mine. Don't go to the dealer this is a simple job maybe takes an hour to finish. The part you need is made by dorman. The two part numbers are 625-100 and 625-001 depending on which set your replacing. most likely it will be the 625-100. if you do a google for "dorman oil cooler lines" you can see what I'm talking about. I went to my local carquest auto parts store and got them for around 30 bucks. I'm telling you seriously go get them you'll save time and money.


Hey thanks for this time and money saving post, was wondering how your lines have held up after this long? Kinda curious as to their durability. thanks again.

You can also buy them on Amazon.com
search - automotive section,
"blazer oil"
http://www.amazon.com/gp/search/ref=nb_ss_auto/102-7272157-4984920?url=search-alias%3Dautomotive&field-keywords=blazer+oil

Whoa, two year bump.

a friend of mine replaced the lines on his 95. he said it took about 2hrs and said he had trouble with the line that connects to the engine block. these things sound like a bitch to replace. by the way, does anyone have the part# for the gasket kit (includes the gasket and o-rings for the remote oil filter) 2 of my o-rings at the filter drip oil if its parked for over an hr.

they're crush washers not o-rings... You can get them at the dealer for 2 bux...:) As for the rear line, an extention and a swivel makes easy work of it.

someone had mentioned before that there is a gasket kit at advanced auto parts that includes the gaskets for the lines attaching to the oil filter, and these crush washers. wanted to know if anyone knew the part # for them? as far as i can tell the lines them selves are not leaking, just the crush washers. With almost 204,000 miles and not knowing all previous maintanence records, the lines may be going up soon.

http://cgi.ebay.com/ebaymotors/94-95-S10-BLAZER-SONOMA-4WD-Oil-Cooler-Lines-Hose-S-10_W0QQitemZ8030430456QQcategoryZ46095QQssPageName ZWDVWQQrdZ1QQcmdZViewItem
is that just considered one line or two.

there is one other listed for a 95;
http://cgi.ebay.com/ebaymotors/94-95-S10-BLAZER-SONOMA-4WD-Oil-Filter-Lines-Hose-S-10_W0QQitemZ8030123304QQcategoryZ46095QQssPageName ZWDVWQQrdZ1QQcmdZViewItem

The Block-to-Filter lines on 1995-only are more difficult than any other year. GM added a steel-rod brace from the engine block to the transmission bellhousing to stiffen the assembly. In 1996 and newer, the aluminum oil pan provides the extra stiffness to the engine-trans connection. 1994 and earlier have a different assembly because the filter is up on the fender, and I don't think they have the brace rods.
The oil line assembly is 2 lines crimped and braised together so they cannot be separated. The engine-to-trans brace passes between the 2 lines, so it must be removed before you can access the rear bolt on the oil lines. Best way to get at it is through driver-side wheel well with a shorty-9/16" wrench.
Also note that you do Not have to jack up the motor on a 1995. There is plenty of room after the brace is removed.

I have a 97 blazer....same problem.

We carry the lines. Dorman 625-100 to the radiator and 626-001 from the filter to the engine.

So is it more likely that it would be these crush washers than the lines?
Mine seemed to start leaking after I replaced the Oil pan and engine mounts.

Also can anyone confirm Autozone having the washer set?

It's the lines for sure.

Mine have been leaking a drop every once in a while for 7 years.

From what I have been told, even the new ones seep a bit.

If anyone needs the quick disconnects for the oil cooler line to radiator, the PN is 800-607. It is a Dorman part and Rockauto.com carries them as well. The GM cross reference is 15719697.

Typically the lines leak where the hose crimp into the pipe. I have a mess under mine but it only leaves one drip on the garage floor every couple of days. Its been like that for 5 years. I am going to change mine when it warms up outside.

I have a 98 4x4 and had the same problem with the lines leaking. I think I paid around $140 in parts (dealer) and did the job myself. It took me a couple of hours, it was a very tight fit to get the lines in. I've heard that the rubber part on the lines can break off and well, no more oil in the engine.
Someone told me that there might be a special filter that would fit on the 4x4's rather than replacing the lines. Don't know if this is true, haven't looked into it, but on the 4x4's is there an alternative to replacing the lines?

No, you will have to change them.

Tough call really, mine have been leaking for over 7 years with no failure, just a slow seep that takes days to form a drop that can fall.

To aid in not blowing them, use a quality oil filter that is not too restrictive on a remote oil filter setup.

Hey everyone,
Yesterday, I just installed new oil cooler lines on my 1998 2wd...
This was a piece of cake job, Under 1 hour.(I TOOK MY TIME) no jacking, and plenty of room to work.
DORMAN OIL COOLER LINES PART# 625-122 = 2WHEEL DRIVE
I rebuilt my old oil lines with 300psi rubber semi truck oil lines and a hack saw, I took about ten minutes to rebuild them, Then my son in law installed the rebuilt one's in his 97-2wd last night. $17.00 spent for his rebuilt lines.... The rebuilt lines seem to be much stronger then the new ones. That's the route I'm going next time...

Hey everyone,
Yesterday, I just installed new oil cooler lines on my 1998 2wd...
This was a piece of cake job, Under 1 hour.(I TOOK MY TIME) no jacking, and plenty of room to work.
DORMAN OIL COOLER LINES PART# 625-122 = 2WHEEL DRIVE
I rebuilt my old oil lines with 300psi rubber semi truck oil lines and a hack saw, I took about ten minutes to rebuild them, Then my son in law installed the rebuilt one's in his 97-2wd last night. $17.00 spent for his rebuilt lines.... The rebuilt lines seem to be much stronger then the new ones. That's the route I'm going next time...

I have to look into this.....

I just replaced my oil cooler line (block to filter housing) on my 1995 Jimmy 4wd. Sorry to intrude on the Blazer forum, I typically look at both Jimmy and Blazer forums and the Blazer forums typically have 4 times the number of posts. I see significantly more Blazer than Jimmies so there must be more of them out there that break. Also I am replying to a 4 year old post but I have not seen a single source of this info out there.
From what I can piece together the 1995 year is harder because of a bracer bar and a 4wd is harder than a 2wd.
I got the Dorman 625-001 lines at Advanced Auto. I checked AC Delco online and they don’t list a GM OEM part for it.
Couple of issues here where I can add to the collective knowledge provided on this particular task to hopefully help others. Many of these lessons I leaned form my experience (took many hours and many not so pleasant words to gain this experience) and elsewhere (i.e. other websites).
1. Remove the two skid plates from the bottom side of the engine. I also remove the fresh air intake housing so you can see everything from above and it allows more light into the tight spaces.
2. Undo the oil line and filter on the filter housing and let the oil drain.
3. The 1995 has an engine to transmission bracer bar that runs through the middle of the two lines. This has to be removed. I jacked up the Jimmy and remove the front driver side tire. I used a stubby swivel head ratchet and a 9/16 (I think) socket to get the engine bolt off. The transmission bolt is simple. Walla the bracer bar is removed. More on this later.
4. You can take a really long ratchet extender (I used two 9” and two 3” extenders) with a swivel joint and put it on the bolt holding the oil line to the engine block. I think it is a 13mm bolt. You can position the socket on the bolt from the wheel well and then turn it from the front underside of the engine compartment.
5. There is a plastic bracer that is almost to the end of the metal part of the line that attaches the line to the engine. I used some needle nose pliers to pop off the plastic part and saved it for reinstalling the new lines. The new Doorman line came with a bracer but it isn’t configured to fit thought I guess you could bend it into place so I removed the one that came on the new lines and used the existing bracer.
6. Now the fun part. You cannot get the oil line out in a 4wd as it gets caught between the exhaust manifold and the 4wd transfer case. This is why I suspect that the 2wd is much easier as it doesn’t have a transfer case. I found somewhere that the solution is to jack up the engine with your floor jack. I jacked using the oil pan. It is steel so it didn’t have any problem other than the floor jack left an impression on the bottom of my pan. Lesson learned; use a block of wood to prevent the impression if this causes you concern. I did it without messing with any engine mounts. You only need about an inch or so of lift to be able to wiggle out the old oil line and to get the new one back in. I have never lifted an engine and it sure pops and pings a lot when lifting. As I was doing this the thought crossed my mind I wonder what it would cost me if I broker something. My wife and kids are always harassing to get rid of my Jimmy and so maybe they would be happy.
7. Important, remove the o-ring washers on both ends of the line. On mine the o-ring washers stayed stuck to the engine block and you cannot really see them that well. Trust me they are there and must be removed. They pop right off and should fall to the ground. The new Dorman comes with a single piece washer that fits on. I left it off when inserting through the engine compartment to keep it cleaner. I put it on from the wheel well prior to reattaching the line back to the engine block. For good measure I moistened with some motor oil. I guess they say do it for filters so why not for o-rings.
8. I then lowered the engine back down and then my long socket with swivel joint wouldn’t fit. This is when I realized that when you lower the engine back down it lowers more than you raised it. I suspect it has something to do with the removal of the bracer bar in step 3 and friction. Not a big deal I jacket it back up more than an inch this time and everything goes back in just fine. Reverse the process, place your bolt on the line from the wheel well and tighten from below. Somewhere I read don’t over tighten this bolt as it is prone to stripping. I tightened to 20 ft/lb.
9. Reattach the other end of the line to the filter housing and tighten to 20 ft/lb.
10. Now the pain in the ass part. Through the process of removing a bracer bar and lifting and lowering the engine the bracer bar no longer lines up. So I put the bracer bar back on the engine loosely and I lower and raised the engine up and down until it fit. I don’t know if it matters but I moved where I placed my jack and it seemed to change which way the engine moved. This took a while with many not so pleasant words rolling off my lips. The lesson learned; I might try bracing both the engine and transmission before starting so that the bracer bar will fit again. I don’t think it’s truly an amount of drop problem as much as it is the relative positioning of the engine to the transmission problem. Anyway I got it back together.
11. Put on a new filter, go ahead and change the oil, and reassemble everything.
I suspect that my filter housing to radiator lines are leaking as well and I might try them another time. They look much easier.

Was surprised to get an email alert that this thread came back to life. Sold my last blazer about 3 years ago, and it is still going strong for the guy that bought it from me. If anyone needs oil cooler lines for a 1994, PM me, as I still have a set in the garage.

wow! thanks for the info. not relevant for me, but i'm sure someone will need it. i'll try to copy/paste that post to a new DIY thread sometime in the next few days (if someone doesn't beat me to it)

I just did my oil cooler lines for the third time in 7 years . these lines are shit . the first set i bought from gm , they lasted about 4 years . then i bought a set of doreman cooler lines they lasted only 3 years . so i decided to fix the doreman lines . i cut off the crimps and flared the ends of the aluminum bought half inch oil hoselines for $ 1.30 a foot . bought 4 feet of it and a 16 hose clamps. first thing to do is to jack front end up , remove skid plates . remove front u joint bolts and let drive shaft hange out of the way . then with a 14 mm stubby wrench i reached in over the front center carrier or diff and removed the bolt holding in the steed rod ( brace). and removed the other end of brace at the bell housing with a 12mm socket . now you need a long extention with a swivel joint and a 13mm socket and remove bolt holding cool line to oil adapter on the engine block. do the same on the filter adapter . now with the oil line loose there is no need to jack up the engine. all you have to do to remove this line is to turn it 180 degrees more or less and the line will come right out without any problems. you might have to wiggle it a bit but it will come out . now take this line to the work bench and cut off the crimps with a die grinder or a hacksaw what ever you have . just cut a straight line along the crimp and peel it off.remove hose. now flare the end of the aluminum line and cut new hose to the same size as the old one . now slip it on all the way to the end of the lip on the line . now i used two hose clamps on it just for extra tightness and with no worry s it will ever come off . now do the same for all other lines . remember to flare and use two good quality hose clamps at each connection and you will have no problems . This is a 100 % repair job better then buying new lines and have to do it ever 2 to 3 years with junk lines . and what i like about this too is that i can always tighten up the clamps a bit to keep a good tight seal . Oh i forgot to mention for those that think this is not a good fix. your oil line have about 65 psi when cold and about 25 to 30 psi when hot . the flared ends and a hose clamp is good for well over 200 psi . so i would say this is a fine fix . I will post some pictures soon . Ciao !