545svk

Hi. My ,87 s4 auto - RHD have sprung a leak.

Coolant bubbles out from the top left hand corner (when facing the car).

Is this a common symptom with a known source and fix? (He asks hopefully!)

Thanks

ThetaTau87

This is a common problem. The leak is likely from the joint between the aluminum core and the plastic end tank or a crack in the end tank. You can have a radiator shop replace the plastic end tank and gasket seal, but they need to be familiar with removing plastic end tanks and reinstalling them without breaking off the metal tabs that hold the plastic tank to the core. I believe there is a write up here on how to DIY the gasket replacement if you search around a bit and you are comfortable to DIY this repair. It's a good idea to read the procedure even if you're going to have a shop do it. That way you'll be familiar with the process and can ask the right questions and tell if the shop is competent to do the repair correctly. Either way you will want to source your own parts. If the shop can source the parts they will likely overcharge you.

Most shops don't repair radiators. They just replace them, so be sure to talk with the tech doing the work to ensure that he's done this type of repair before.

I had a leaking oil cooler inside one of the end tanks. I was able to find a good used oil cooler and install it in a new end tank then have a shop install the end tank with a new gasket. The repaired radiator is leak free and the cost was a fraction of buying a used radiator.

Randy V

Very common.

Find the thread that shows you how to repair it yourself.

Save $3000

545svk

Thanks guys. Will search and try.

If I break it, it needed replacement anyway

545svk

https://rennlist.com/forums/928-foru...h-no-tabs.html

Hilton

Not that way.. you'll break tabs.

DO it this way:

https://rennlist.com/forums/diy-subm...king-tabs.html

I'm hoping to get permission to add the pics back, or at least a pdf with the pics - basic story is pry up the whole edge, rather than individual tabs.. then clamp with new tank in place, and tap edge back into place (thus pushing the tabs down again) with a hammer.

edit: Also, its most likely the leak is from a crack in the plastic end tank, and not the gasket. Just replace the whole end tank and be done.. instead of doing what I di and replacing just the gasket only to find it still leaked, and having to do it again Many heat cycles and hot coolant weakened the plastic where it comes in hot from the engine.

545svk

Thanks Hilton

Looks like I am going to learn new skills.

davek9

Wow haven't seen that old thread in awhile

Yes my way involves fabrication and is great if you have broken tabs or just don't want to deform the edge of the core. (by the way the radiator pictured in my post is still in service w/o leaking on my 85.

I have also used the edge bending method on two others with also good results, one thing I noticed is start with a small screwdriver and go round and round then move up to a larger prying tool.

Don't try to get it apart in one shot, also you do not need complete clearance, just enough to get the tank out, less bending the better (I also coat the new seal w/ some water pump grade gasket sealant).

The main thing is to get the End tank off and inspect the core, if it's not clean/unblocked, get a new Rad.

Dave K

Jetdriver69

Or you can order an aluminum replacement radiator from 928 Motorsports or 928 International for a fraction of a Behr, if you can find one.

Ive had one in my 82 for 18 months and the cooling qualities are much higher than the old Behr. But in fairness, the Behr was 32 years old.

Tom in Austin

Yeah, Mark Anderson's new aluminum jobs are nice ... and repairing a 1980's vintage Behr is a stretch. I had my end tanks replaced and it went bad about a year later.

Mongo

You can only repair once. The second time around the metal tabs break. When that happens, go all aluminum.

I am dreading this day again....

Hilton

Someone else saved the pics too.. here:

http://jenniskens.livedsl.nl/Technic...8/MyTip862.htm

545svk

Thanks Hilton

JHowell37

Go for it.

Hilton

Cool, thanks.

Here's the PDF on how to replace radiator end tank without breaking tabs