Coolant leak

[mjtjnj]

On my 2000 TJ Sport, I've spent the last year (3 kids) replacing the entire suspension and doing needed maintenance. I had a leak from the thermostat housing, and when I took it off, it was like green Jell-o. Right away I knew someone had been using stop-leak. Sure enough, after flushing the cooling system, I noticed a coolant leak from the bellhousing, pretty consistently. Not a slow leak. From what I've read it's either going to be the freeze plug on the back of the head or under the bellhousing on the back of the block. Obviously, it could be the head, too, but I'm not seeing any other signs of a head gasket leak. If it's the plug on the back of the cylinder head, is it easier to pull the trans and tilt the block, or just pull the head. Pulling the head is a pain, and always has the possibility of a leaking new head gasket because I wasn't careful enough

Has anyone done one of these? Another TJ had a drip from one of the freeze plugs under the exhaust, and I just left it alone, but this is a much more brisk leak. What is involved in pulling a plug and re-installing?

Thanks--
Tom

 

[RMETeeJay]

You can borrow a pressure tester from your FLAPS. While under pressure, use a mirror to pinpoint the source of the leak.

I've thankfully never had to do a freeze plug, but from what I've read it looks pretty straightforward (other than access issues).

 

[P man]

First thing you need to do is verify where the leak is coming from. Do you own a pressure tester? If not go rent/borrow or buy one.

Clean the area thoroughly and put pressure to the system. Get those kids good lighting and have them help you pinpoint the leak.

If it happens to be a freeze plug you have a couple options. The cheapest and quickest way is a rubber expansion plug.

If you want to install an oem freeze plug you need room to get it started straight and tap it flush. It isn't easy on the workbench and it won't be easy under the jeep at odd angles.

 

[mjtjnj]

Thanks, all. Gonna get my hands on a pressure tester. FWIW, I didn’t feel any wetness under the head freeze plug, just some grime that didn’t smell like antifreeze. Could be the head gasket.

Fun!

 

[Gollywomper]

If it is a freeze plug and it is leaking from corrosion I would pull the motor and change the all. If it is just a bad seal on the plug then change just the leaker.