Fitting thread and size to attach a hose to the block plug

[SGT John]

I am getting ready to do a de-oil and flush on the coolant system of my 85 300D. I saw this weekend that unless I could get my hands on a proper hose fitting to go in where the block plug comes out, I will make a huge mess and there would be no way for me to collect and properly dispose of ALL of the coolant.

Does anyone know the proper thread type and size of the plug?

[LUVMBDiesels]

1/4 inch galvanized pipe will fit right in. I use a small 2 inch nipple, then a 90 degree elbow and then a larger 8 inch nipple to go from the block down past the motor mount. Then I stuffed the end of the nipple into a piece of clear drain hose (reinforced garden hose) I put a normal garden hose fitting on the snd of the hose. Now I can drain the block, then attach the hose to my garden hose and back flush the entire cooling system.


I have posted a picture of my setup on the forum. Look for Citric Acid Flush posts under my name...

[mobetta]

M14x1.5, i believe.

[SD Blue]

Originally Posted by LUVMBDiesels

I have posted a picture of my setup on the forum. Look for Citric Acid Flush posts under my name...

Hmmm, I searched through 13 posts using "citric acid flush" and "luvmbdiesels" and did not find any pictures of this setup. BTW, it sounds like a good method for reverse flush. Did you use any sort of check valve to prevent reverse pressure from possible contamination of the water supply?

[Mister Byrnzoil]

heres the thread, post 22

If I have the dreaded green coolant...

pics are here

http://share.shutterfly.com/action/pictures?a=67b0de21b35084ec2558&sid=1FbM2LVixdQ

Only thing that concerns me is putting SAE pipe thread into a metric thread hole...bugger those threads and you'd prolly hafto pull the intake and exhaust manifolds to re-tap it.

[SGT John]

good work on the plumbing. I was thinking just a nipple with a 18" piece of hose on it. I want everything possible to go into the bucket, instead of onto my lawn, where I will have to lay to get the plug back in.

[Mister Byrnzoil]

I just use a 2' x 3' plastic tub, (also used for mixing concrete and mortar) pretty much catches everything... no backflush option tho.