Finding a good shop is getting hard now,All the old real mechanics are retiring off and the younger replacements are part changers.A true mechanic figures out whats wrong then fixes it.A part changer is just that they throw parts at it tell its fixed or they give up.

 

Take it to your local high school's autotech class next time... The teachers usually know their stuff, and aren't trying to rip you off.
Plus you know he checks their work, si ehhh.

Just my two cents.

 

they jacked up the BACK to burp it?? If anything, you would jack up the front of the vehicle so that the radiator cap is the highest point in the system and will bleed properly and efficiently; although on the jeep, the radiator cap is already the highest point with the vehicle level so it's not even necessary.

If they 'bled' the system with the rear of the vehicle jacked, the head would have a huge air pocket in it.

 

On a renix you can burp it by jacking the rear of the jeep up and releasing excess air through the coolant temp sensor on the back of the head. The renix jeeps have no radiator cap, just a piece of crap plastic tank with a pressure cap.

 

Only way to burp a renix is to jack the *** end up and loosen the temp sensor in the back drivers side of the head. If your lucky and park it in driveway with a good slope to get the nose of the jeep high where the front of the motor is higher then back, then you can fill from the heater hose connection on the thermostat housing. Then just top off the coolant bottle as needed. Works good for me.

 

I think that's what the OP meant when he said "thermostat".

Since 1987, myself and a crew of 3 techs never burped a Renix cooling system on a 4.0 Jeep through 1992.

With no issues.

I'm thinking that the increased occurence of needing to burp them is because the replacement caps now are all chinese junk. On top of that, the replacement bottles are made cheaply and the caps don't fit well.

I use only the 703-1396 cap from Napa.

Here's how the FSM describes to fill a Renix system.


Check this out from the FSM

This system does not have a radiator pressure cap. Instead the pressure cap is mounted on the coolant pressure bottle. System coolant flows directly through a fully pressurized Hot-Type expansion bottle. Coolant flows through the pressure bottle at all times during engine operation whether the engine is cold or at normal operating temperatures.

Larger coolant volume caused by thermal expansion during engine operation is absorbed by the expansion chamber in the bottle. Air trapped in the system is purged through the pressure cap vent valve during maximum coolant expansion..

 

So would that be the little one way valve sitting on top of the pressure bottle opposite the cap? I always wondered what that thing was

 

Naw. It IS the cap. A real one. Like when they were new and didn't have chinese POSs as caps. You know, the olden days. Before Clinton gave china "most favored nation trading status".

 

Thank god the jeep got i6...working on a slant 6 wouldn't be fun is imagine

 

Chicom won't take kindly to you & I picking on them, I fear our days are numbered.