Blocked coolant pipe

[sterl]

Hello All. Does anybody know how to unblock the U-shaped metal coolant venting pipe at the front of the engine that goes from from the top of the water pump housing to the cylinder head? I've tried poking wire through without success. Thanks in advance.

Mark

Billericay, Essex, UK
Late 67 LHD 250SL

[ctaylor738]

Soak it in carb cleaner overnight, then blow it out with compressed air.

Chuck Taylor
1970 280SL #14076
Falls Church VA

[sterl]

Thanks Chuck. I did manage to clear it with a cycle brake cable and penetrating oil. After 2 hours of gouging it was not only my nerves that were frayed! Anyway, it did work and there was a small sense of achievement...

Thanks again
Mark

Billericay, Essex, UK
Late 67 LHD 250SL

[merrill]

Mark,
how did you know it was clogged?

Matt

Matt
66 230 sl - "white"
78 300 D - Blue
98 C230

[sterl]

Matt, I have the head off and was cleaning everything up. It's very small for a coolant pipe and I thought originally it was an oil pipe. It's probably to help prevent air locks, but I'm not sure. Anyway I just thought I'd check it and it was badly clogged. The head's never been off before so there's 40 years of crud build-up in it. Bet other's have the same problem!

Does anyone know what effect a blocked pipe has?

Mark

Billericay, Essex, UK
Late 67 LHD 250SL