M42 Radiator expansion tank

[KenC]

The side mounted expansion tank on my radiator has developed a small leak at the bottom of it. Is it removable? I think I need to re-seal it. The radiator is fairly new so I don't want to replace it.

[Roadsterd]

Yep. Pull it off, reseal it with some silicone and your good to go.

[BBY1104]

Like he said it is removable, When I did the radiator on my last car, I bought this stuff that was a bunch of capsules and tar called Radiator Repair. You pour it in the top and it creates a coating on the inside of the radiator. It fixed a couple small leaks.

GL

[devonjordan]

Sorry to bump an old thread but...

is this where the leak was from?


Because if all I have to do is reseal it, thats AWESOME!

[Schneller 3er]

I have a nice radiator, like new, that's laying around collecting dust, if anyone is looking for one. New are like $190...SOLD

[bats]

Sorry to bump an old thread but...

is this where the leak was from?


Because if all I have to do is reseal it, thats AWESOME!

drain the tank, pull the top two hex screws, pop the top 'cover' off, and yank the tank off. apply rtv and you're set.

[flying_violin]

^^ I bet I'm about to sound like an imbecile, but I drained the tank today, pulled the top two hex screws, and removed the bleed screw, but for the life of me, could not figure out how to "pop the top 'cover' off." The cover seemed to be securely fastened to the radiator. And I even undid the plastic rivet that holds the fan shroud on. Am I missing something, or do I just need to pull harder?

[KenC]

Pull harder. The expansion tank is going to be difficult to remove as well. Get new rings and seal them with silicone and you should be good to go.

[Grand525]

IIRC it has an O-ring wraps around the bottom neck of the expansion tank.
Use hair dryer would help to soften the area, right before you pull the tank off.

[SedanSandwich]

http://realoem.com/bmw/showparts.do?...02&hg=17&fg=05 Part # 3 if you want to replace the oring instead of using silicone.

[bmwman91]

It is a bitch to pull the tank off. When reinstalling it make sure to lube the new rubber o-rings with some silicone dielectric grease so that they don't pinch/tear when you jam the new tank in. It is a big PITA.

[Joerdan23TN]

Uggggg!

I have been going through hell fellas, i need some advice.

My expansion tank was seeping at the bottom. My car was not over heating or anything.
I bought a new expansion tank and both o-rings from pelican parts. I put the new parts in, easy enough. I then proceeded bleeding the system. Awesome, I got my heater working better then ever and restored a slightly pulsed idle to normal.

Throughout bleeding the system I developed a leak at the bleeder screw. I bought a new bleeder screw today at BMW and expected to go home pop it on and be good.

The new one is leaking too. I actually can not tighten it down without it popping free and needing to be re-tightened. <Same problem I had with the last one randomly.

Oh and i look down and my expansion tank is leaking just like the last one.

I need to go to work tmrw and i'm getting super frustrated.

[irish44j]

sounds like the thread on the rad itself for the bleeder screw may be stripped?

[jrobie79]

bavauto sells a brass bleeder screw, might help

[AdamPlaysDrums]

Nice way I found to get the tank off a bit easier: use a flathead screwdriver and hammer, get under the car and tap away at the gap between tank and radiator. Once a decent gap is opened use a bit more force, and the tank pops off nice and easy..er like. Getting it back on is still a bitch though.