did the oil cooler lines. some thoughts-- - PeachParts Mercedes-Benz Forum

Nate Stanley · #1 01-03-2005, 03:38 PM

yippee! It's over! They are in!

If you see any leaks at all from your old lines, you can be sure the inside of the flex lines are cooked hard as rocks and you are on borrowed time. When I took mine out, the lower flexible part of line could freely swivel on the crimped steel fitting.

Some Suggestions, and this is not intended as an exact how-to-guide:

1) I agonized over whether or not to remove the motor mount first. Go ahead and do it. It's so easy to get the lines out that way. Sure, the 4 nuts holding the aluminum casting are a pain to get to, but they can be removed. If your hoses are shot, your motor mounts may be as well. I had to redo the turbo oil seals and return pipe seals, and replace my exhaust pipe as well, so I had the passenger side motor mounts readily exposed after I yanked the turbo and intake manifold.

1A) yank the battery and battery tray. You need to check for rust under it anyway. This will buy you a little more room there in which to work.

1B) Use PB blaster on all exhaust nuts. You may not need it since Mercedes had the good sense to copper-plate all exhaust releated nuts to prevent seizing, but use it anyway.

2) Drain the oil a week before you begin this job and be sure to pull the oil filter as well so the oil filter housing can drain too. Buy a lower oil pan gasket (see 9)

3) get a pair of pruning shears and cut the flex lines as close to the oil cooler as possible. Remove oil cooler and proceed to (4)

4) (from another poster, I second this!) get a pneumatic cutoff wheel for 2 reasons. One, to chop the end off a cheap crescent wrench in order to get a good swing on the lines where they attach to the oil filter housing. Two, to surgically remove the nuts that screw onto the oil cooler. Corrosion will set in over 20 years and you may strip the threads on the aluminum cooler if you just muscle the pipe fittings.

4a) undo the power steering lines at the steering box and swing them out of the way. You will need all the room you can get. You probably needed to replace your PS fluid anyway. This will start the process.

5) Once the remains of the oil cooler lines are out, back out the 2 steel fittings that are in the oil filter housing. Clean them up w/ brake cleaner, and reinstall them with blue loctite and cinch them down HARD. That way the next guy (it may be you, you know) will not have to put a second wrench on those fittings the next time you take off the lines.

6) there are two ways to reinstall the new lines, one is correct and one is not-- it will allow the steel tube sections to rub against another and possibly spring a leak over time. Take a digital photo or refer to appropriate pix in the manuals to verify proper installation.

7) Now is the time to replace the oil filter hsg gasket if the gasket is leaking. (mine wasn't)

8) Use anti-seize compound to coat the threads of the oil cooler lines upon reinstallation.

9)Lower Turbo oil return pipe- I couldn't pull mine out even with a 22mm wrench used as a pry bar under the end of tube, using the motor mount casting as a fulcrum. The grommet was rock-hard and even when cut away from the upper surface of the oil pan.

If this happens, bite the bullet and drop the lower oil pan. Stick an appropriately-sized socket on an extension, and use a jack to force the tube up from down below. It MUST yield.

10) Check out that air filter bkt. Mine came out in 2 pieces. Since it was a holiday weekend and weather was not cooperating, I didn't have time to use regular channels to mail-order a new one. Stahl Motors in Monterey had one for 123 dollars, (shame, shame) so I went to the hardware store and got some flux-coated brazing rod to repair the old one using my MAPP gas torch. I used a couple of pieces of scrap metal to provide reinforcement, and a little dry Boraxo hand soap for extra flux (My dad taught me that one) , and it is now better than new.

11) Don't get frustrated. Take your time and remember you are paying yourself for extending the life of a fine engine. Most fasteners can be reached using an extension / u-joint combination. Get box wrenches and sockets ready and let your patience become a virtue. This is great training.

BTW I need a few more hours before I get it totally buttoned up, and I'll post results later.

Eric Eliel · #2 01-03-2005, 09:22 PM

Nate,

I know you feel better after taking off the oil pan (to replace the steel turbo drain pipe) and it isn't that bad of a job IF you have replacement screws after the socket head screws are buggered up. BUT you don't need to pull the pan.

Attached a hose clamp to the steel down pipe of the turbo drain. Tighten clamp, put big screw driver under the clamp and hit it with hammer. This will drive the pipe upwards.

$123 for the air cleaner bracket!!! Rip off of the century!

Nate Stanley · #3 01-04-2005, 11:36 AM

Actually, None of the SH screws gave me a problem with the entire job. There was enough oil on the threads to make removal pretty easy.

As for cracking the oil cooler fittings loose with one big whack, I was not in a position to risk this. When it's a holiday weekend and you don't have another one laying around, you work with the oil cooler you have, not the one you'd like to have.

It was well worth the time to baby this one. The first 3 threads had already been stripped off on the upper fitting from some previous attempt to loosen the lines, and I felt that gritty crunch when I tried to loosen it some more. Believe me, the cutoff wheel paid for itself that day.

Eric Eliel · #4 01-04-2005, 12:52 PM

I was speaking about whacking at the lower turbo drain line, not the oil cooler lines. I agree with you that you have to be very careful with the oil cooler fittings.

Nate Stanley · #5 01-04-2005, 01:28 PM

the whack was in reference to mespe's post (see above), no problem---