Coolant seep from freeze plug - PeachParts Mercedes-Benz Forum

2dieseljohn · #1 08-23-2008, 12:38 PM

I found this bit of coolant when I took off my turbo on my 79 617 to change out my gaskets. The seep

is clearly coming from, not sure if this is the right term but my "freeze plug". There is a small crust @ apx. 9 O'clock. I tried a search but could not come up with much. Any experance-JB Weld, knock it out and replace? Thanks

Carson357 · #2 08-23-2008, 01:47 PM

knock it out and replace it, it is called a freeze plug, hopefully the block is not pitted, you also need to get that green coolant out of there and put in the correct MB coolant, be sure to flush system with garden hose to get it out of heater core and other areas
if the block is pitted you can likely use the jb weld to fill in the pits for a proper seal

blindwolf · #3 08-23-2008, 01:57 PM

You will find that when one freeze plug goes, the others are or wiil be soon, in the same shape, Replace all of them that you can get to at the same time and keep a wary eye on the ones you did not change out.

2dieseljohn · #4 08-23-2008, 02:24 PM

Thanks all. I feel a lot better. Part of what I'm doing is a Flush and then a Block warmer. I was told by the PO that the coolant was rated for all cars but it's one of the things that has always bothered me. I'll call Phil on Monday. Cheers-

Diesel911 · #5 08-23-2008, 07:57 PM

JB-Weld would most likely be a forever fix.
I like JB-Weld but have always used that old messy brown hardening type Permatex on Freeze/Core plugs with no problems. I clean the hole area with 180 grit emery paper to get rid of the loose rust. It is best if you can see the bare metal. Degrease with brake cleaner before application of sealant.
If you decide to replace all of the plugs solid Brass (not plated) Freeze Plugs last longer (at least on gas cars).
I have replaced one with Brass while the others were steel with no problems but I don't want to start an argument concerning Electrolysis and dissimilar metals; use your best judgment.

Biotour · #6 11-02-2009, 12:24 AM

how would one go about knocking out the old freeze plugs and replacing them with new?

is this job possible with the engine in the car or must it be hoisted out?

leathermang · #7 11-02-2009, 08:17 AM

LOL,
' Engine hoisted out ? '
I once had a 1957 XK140 Jaguar fixed head coupe. The head had a freeze plug on the rear next to the firewall... I really mean next to the firewall... like ONE INCH working distance in there... so, being about 24 at the time I pulled the whole cast iron 6 cylinder engine out of the small hole covered by the " bonnet " . This is a car which the manufacturer decided it was OK to mix American threads, Metric Threads AND WENTWORTH threads into one car without any way to tell what you were putting a wrench on... Never got it all put back together... put a 225 slant six Dodge engine into the chassis with the body off... but never got the body back on... had moved on to my 1934 Plymouth Coupe.....
I always ran plenty of antifreeze in my cars... and this is central Texas... I could have cleaned the block around that freeze plug and epoxied brass shim stock over the freeze plug and never had any more problems with it...
But when one CAN access freeze plugs ( actually MB calls these things something like ' block core access holes ' instead of freeze plugs). the proper way to do this is to remove and replace. It is easier than it looks most of the time since you just hit on one side of the plug and it turns 90 degrees and you grab it with pliers and pulls it out... then clean the block hole really well... put something like Aviation gasket cement onto the new brass plugs and use a socket to tap it in straight... it is nice if you are a machinist to make a plug installer with a lip on it which will not allow the plug to be seated too deep... in some instances where things are tight rubber plugs are available which can be installed and held by tightening them with a center bolt...
In any case cleanliness is really important...
Even a small leak anywhere means your cooling system is not pressurized.. so you are not getting the cooling effect of using a radiator cap.....

2dieseljohn · #8 11-02-2009, 11:37 AM

Biotoure- I did a DIY for this Guide to Replacing Freeze Plugs I think this will help you. This was a pretty big job, but not hard. Were here for you and can get you thrugh this.
Regards
2dieseljohn

stimpy451 · #9 11-02-2009, 01:39 PM

Quote:

Originally Posted by leathermang

LOL,
' Engine hoisted out ? '
I . This is a car which the manufacturer decided it was OK to mix American threads, Metric Threads AND WENTWORTH threads into one car without any way to tell what you were putting a wrench on......

Never worked on a British Motorbike, eh mate?

I have more Whitworth sockets than SAE

Biotour · #10 11-03-2009, 01:31 PM

2dieseljohn- thanks for the link to the DIY. looks pretty straightforward. unfortunately the ones that are leaking the most are on the other side of the engine by the ip and oil filter housing. have you done those yet on your car? any tips?

leathermang · #11 11-03-2009, 02:48 PM

Quote:

Originally Posted by Biotour

unfortunately the ones that are leaking the most are on the other side of the engine by the ip and oil filter housing. have you done those yet on your car? any tips?

He did half the tutorial...
and left the other side for you to do...
We expect great pictures and complete instructions...
LOL

2dieseljohn · #12 11-03-2009, 05:29 PM

Well said Leathermag

- I would think it might not be so bad: as only the IP and cooler lines

(might as well replace them along with mounts, etc..). Take your time and use this forum and lots of pics.
regards

Les Jenkins · #13 11-04-2009, 12:28 AM

A small dab of JB worked perfect for me. Far better than pulling the IP.

kerry · #14 11-04-2009, 09:10 AM

For the record, I had a cracked hot water radiator in my house 20 yrs ago. I covered the crack with plumbers epoxy. It still holds today.

2dieseljohn · #15 11-04-2009, 05:49 PM

Interesting you should bring up plumbers epoxy. I grew up in Nevada and (misspent) most of my life as a avid off road driver/explorer. The old Desert Rats that we learned from always had a "Hell Box" in it was all kinds of useful stuff . Plumbers Epoxy was something everyone carried. Who knows it worked on the old Jeeps.