Heat Control Vacuum Lines

[Keyav8r]

There are two vacuum lines that run from the heater control through the firewall (above the heater core and AC evaporator connections). One is black and goes to a vacuum connection beside the relay assembly on the right fender well. I assume this line continues to the vacuum reservoir behind the front bumper.

The other vacuum line is purple (inside the cab), but mine is bleached out to a pinkish/whitish color in the engine bay. This line pulled loose while I was removing the heater box and I don't know where it is supposed to be connected. It has a short section of vacuum hose on the end which I'm assuming is to connect to another vacuum line but I can't find a loose line on the right side of the engine bay.

Does anyone know where this line connects?

No photos as I have to re-learn Photobucket upload/download/attachment again. It's been said that the mind is the first thing to go and I believe the short term memory is the leader in that parade!

[ParadiseMJ]

[HOrnbrod]

My advice: Plug that vacuum line and eliminate the troublesome water control heater valve entirely by running heater hose straight from the water pump to the heater core. The valve was eliminated on 1997 and up models anyhow. Works fine - lasts a long time. :cheers:

[jimoshel]

It's been said that the mind is the first thing to go and I believe the short term memory is the leader in that parade!

I've always heard that the mind was the second thing to go. I forget what was first.

[Keyav8r]

ParadiseMJ - well, doh! The reason I couldn't find where that line went is because I've got the radiator (and that valve) out and all the hoses off for replacement! I knew I should have taken a photo or ten when I pulled the hoses off. Thanks for the photo.

 

Don - seriously considering doing away with the valve. From what I've read it doesn't seem to have any effect on the performance of the heating/ventilation system if it's removed. And, it would make the engine bay a little less messy looking.

 

Jim - of all the things I've lost, I miss my mind the most.

[cruiser54]

ParadiseMJ - well, doh! The reason I couldn't find where that line went is because I've got the radiator (and that valve) out and all the hoses off for replacement! I knew I should have taken a photo or ten when I pulled the hoses off. Thanks for the photo.

 

Don - seriously considering doing away with the valve. From what I've read it doesn't seem to have any effect on the performance of the heating/ventilation system if it's removed. And, it would make the engine bay a little less messy looking.

 

Jim - of all the things I've lost, I miss my mind the most.

 

Do as Don suggests and don't look back.

[jimoshel]

:agree: Yeah!

[Keyav8r]

I actually just got back on the forum to find a thread to tell me where/how the pressure bottle is tapped into the heater hoses and found your supporting recommendations. Going that way when I get the heater box hung back on the firewall (new heater core). I've got all new hoses and plan to change the crank pulley (little bit of rubber poking out), thermostat (195 degree), belt and idler pulley. The truck had a new water pump on it when I bought it and the radiator and AC evaporator have been replaced. AC isn't currently working and has no Freon in the system but we have a refrigeration tech in our service department who might take care of it in return for the donation of a few adult beverages.

[ParadiseMJ]

Do as Don suggests and don't look back.

 

That's my old stock picture of my XJ (R.I.P)...The 88 MJ has no valve. I found that when I plugged the line I used a screw, somehow it was still sucking air. I capped it with a cap and some sealant. Works mo' betta.

I also have a squeaky clean heater core.

 

BEFORE

 

 

AFTER!!! B)