continuously leaking heater valve...

[luvherinmyjeep32]

i have an 89 XJ and i converted to the 91+ open style cooling system. i bought a 91 XJ heater valve from adv. auto and im n about the 5th one now, because they keep leaking coolant out of the small hole in the side where the metal arm from the vac. diaphram enters the plastic piece to control the valve, only when vacuum is applied though. at first i had it plumbed incorrectly but now im pretty sure i have it right...

left side goes to heater core and you can see the orientation of those hoses on the core at the far left in the picture. top right goes to the t-stat housing and the bottem right goes to the waterpump. is this correct?

any thoughts on why these things keeps going bad? are the ones from adv. auto junk? does the valve need to be mounted in a different position maybe?

 

[luvherinmyjeep32]

i think im just goint to eliminate the valve, cap the vac line, and connect the hoses together. does it matter which way the hoses are connected together, or to be more exact, which way the coolant flows through the heater core?

 

[GroversXJ]

I did the same conversion last summer and I purchased my heater valve from Autozone and mine too was leaking 1 month later. I couldn't find my reciept so they wouldn't exchange it so I pulled it apart (took out the 2 screws, pulled the vac motor off the valve) and made my own rubber gasket from an old inner tube and put it around the metal bar coming out of the valve then put the vac motor back on and screwed it back together. It hasn't leaked since then. I was worried at first that with the added friction of the rubber gasket would keep the valve from opening when winter came around and I'd not have any heat but the heater works good still (now that its winter) so it must not have been enough friction to be a problem.

The only problem I can think of is if the valve is normally open to allow water to go to the heater at rest and the vacuume motor closes the valve when you don't want heat and only A/C. Its possible my setup is allowing hot water to go thru the heater core during the summer, but my A/C did feel a little cooler last summer after I did the conversion so I still don't think its a problem.
I hope it helps.

 

[luvherinmyjeep32]

thanks for the info. i dont have AC anymore BTW.

 

[lawsoncl]

I eliminated the valve when I did my conversion. I don't believe it matters which way you hookup the hoses. The flapper valve in the dash prevents air from flowing through the heater core so it really doesn't make much different if it's hot or not. I never noticed it being warmed in the cab in summer (no a/c) after I did the swap.

Most later models don't have a heater core bypass valve.