Backing up oil cooler hose wrench - PeachParts Mercedes-Benz Forum

kerry · #1 06-10-2011, 05:14 PM

How are people backing up the wrench when loosening the nuts at the filter housing? I'm going to have to replace my hoses on the 84SD in the near future so bought the 1 1/16 wrench. Put it on the top outer hose nut on the housing just to see if it would easily loosen. Something broke free but I'm pretty sure it's not the compression nut but the threaded fitting that goes into the housing. How are people getting a wrench on that fitting? Looks like it might be 25mm or something like that but there's very little space between the compression nut and the fitting 'nut' and it appears that the wrench must come in from the side and not from above giving the location of the boss on the housing. Does anyone know the exact size of that fitting? Even with the correct sized open end wrench ground narrow to fit in the slot and cut off to be short enough to slide in from the side, it doesn't seem you could get enough leverage to resist the torque from the compression nut wrench. Am I missing something?
I don't think it's possible to unthread the fitting with the compression nut tight since it's not free to spin on the metal line. Maybe I could just cut the metal line, remove the fitting and then separate the compression nut and the fitting. Have people done that?
At least the top fitting on the oil cooler loosened easily.

Diesel911 · #2 06-10-2011, 06:57 PM

I do not have the same year and model but I had to grind the head thinner on the Wrench I used to back up the fittings on the Oil Filter Housing that the Oil Cooler Line Hoses screwed onto.

One member of one of the Mercedes fourms cracked his Oil Filter Housing by not using a back-up Wrench on the Fittings.

kerry · #3 06-10-2011, 07:04 PM

Quote:

Originally Posted by Diesel911

One member of one of the Mercedes fourms cracked his Oil Filter Housing by not using a back-up Wrench on the Fittings.

That's why I was testing the nuts today before my hoses arrived. I wanted to see if the nuts would loosen with just moderate pressure to avoid a broken filter housing. Unfortunately, the fitting loosened instead of the nut.

compress ignite · #4 06-10-2011, 11:05 PM

Bicycle Shop,Spanner

They'll be able to get the Flat,Thin Wrench necessary. (In an MM size)

Reasonable Cost.

Diesel911 · #5 06-11-2011, 12:59 AM

In my case I had a set of cheapie combination wrenches made in India or China I just picked size I needed and ground it thinner on a Belt Sander.

I had to buy one I bet it would be less than $5 at the local Cheapie Tool store.

kerry · #6 06-12-2011, 03:34 PM

For the record, fitting 'nut' is 24mm or 1 inch. HF sells a set of large (20-36mm) thin stubby service wrenches. Currently on sale for $31. Skinny enough to fit on the nut. Also bought a set of angled opened end wrenches. Haven't checked to see if they are too fat to fit on the nut.

See John's reply below--it's not 1". May be 15/16" if you're lucky.

vstech · #7 06-12-2011, 03:58 PM

Quote:

Originally Posted by kerry

For the record, fitting 'nut' is 24mm or 1 inch. HF sells a set of large (20-36mm) thin stubby service wrenches. Currently on sale for $31. Skinny enough to fit on the nut. Also bought a set of angled opened end wrenches. Haven't checked to see if they are too fat to fit on the nut.

For the record... 1" is 25.4mm so a 1" wrench would be pretty sloppy on the aluminum fitting...

Stretch · #8 06-12-2011, 04:14 PM

Hey kerry if you are going to replace the lines would you see if my hunch about removing a mounting bracket works on an OM617 turbo?

http://www.peachparts.com/shopforum/showthread.php?t=273282

I know it does on a non turbo... it made the job a lot easier for me.

kerry · #9 06-12-2011, 04:17 PM

I read your hint and another post which said if the oil cooler was removed, the lines could be pulled out thru the front where the oil cooler was. Wont work on my 84sd. The AC condensor is in the front of the oil cooler so even if the oil cooler is removed, there's no hole to remove the lines. Looks like the lines will have to come out to the side under the motor mount.

Stretch · #10 06-12-2011, 04:27 PM

Quote:

Originally Posted by kerry

I read your hint and another post which said if the oil cooler was removed, the lines could be pulled out thru the front where the oil cooler was. Wont work on my 84sd. The AC condensor is in the front of the oil cooler so even if the oil cooler is removed, there's no hole to remove the lines. Looks like the lines will have to come out to the side under the motor mount.

OK fine - not extra space at the front but the lines are flexible closest to the oil cooler right? You should be able to bend them out of the way...

So how about not jacking up the engine and removing the mount but instead remove a support bracket instead? Does that sound easier?

Just remove this second bracket

...and I reckon you've got enough space to pull the hard lines out.

Tie-wrap the flexible line at the front to itself to make it smaller?

See what you think - no pressure - honest gov!

kerry · #11 06-12-2011, 04:36 PM

I'm willing to take a look but with the AC compressor right under them I think it will be difficult. I know someone did it on an earlier model with the York compressor which is on the other side of the engine. I'll look closely.

Stretch · #12 06-12-2011, 04:47 PM

Thank you very much - don't waste too much time on it - I'm just a nutty European without any extras on his non-turbo 300D

kerry · #13 06-12-2011, 04:58 PM

John is correct, my conversion is incorrect. I was basing my initial size guesses off a non-measuring external caliper and I initially thought 25mm and 1" The 1" is too loose. Maybe a 15/16" will fit on it but I'm guessing that will be too tight.
I checked the HF angle wrenches. They will just slide on to the nut in the existing space but in OE condition, depending on where the flats of your nuts land, I don't think it will work to hold the fitting. Grinding the wrench a little thinner may allow it to work. The HF angled standard metric box end wrenches are long enough that the top of the wrench hits the 'ear' that is on the oil filter cover. Maybe with the cover removed it would stand straight enough to slide fully on to the nut.
So the 24mm skinny stubby is the best fit, but whether a person can hold that fitting with a stubby wrench while loosening the compression nut is another issue altogether. I'll keep you posted.

vstech · #14 06-13-2011, 12:14 AM

Quote:

Originally Posted by kerry

I'm willing to take a look but with the AC compressor right under them I think it will be difficult. I know someone did it on an earlier model with the York compressor which is on the other side of the engine. I'll look closely.

My a/c was inop anyway, so on my 82SD I pulled the compressor and mount, and the lines went right in. no lifting the motor! easy.
it's only 3 bolts holding the compressor in.

kerry · #15 06-13-2011, 11:42 AM

Got the outer hose on the oil filter housing figured out. Standard 1 1/16" open end on the compression nut and 24mm HF short stubby wrench from their kit of short open end service wrenches #93668. Put the 24mm on the fitting 'nut' and put a 2x4 between that wrench and the oil filter housing. Then use the 1 1/16" open end to loosen the compression nut. Won't be able to work on the inner hose nuts until the outer hose is removed. New hoses haven't arrived yet.

http://www.harborfreight.com/15-piece-metric-service-wrench-set-93668.html