I have replaced the flimsy heater control valve once already in the last few years, and the new one is leaking more and more lately. Instead of replacing it, again, I want to bypass it. Now I have searched and concluded this is possible by just running the lines from the tstat and pump to the input and output of the heater core, and then plug the vacuum line.

Is the nipple on the heater core inlet/outlet going to be a problem when running my new lines to it? I think they might be a bit bigger, but haven't looked yet. Also, is there just plain strait coolant lines I can buy, or what is my best option here? I have the ability to tie in to a fitting on both lines about a foot or so from the control valve. Is there a better place to plug that vacuum line than right at the end, can I cut it further back and just crimp the line?

Thanks!

 

Most parts stores sell heater hose, in various IDs, by the foot......measure twice, cut once. Doesn't really matter where u seal the vacuum line, as long as it is sealed/capped.

 

Thanks for the reply, just posted this question on the post above but...are the hoses going into and out of the control valve the same size? So i wont have issues running the same diameter hose from the tstat and pump right into the heater?

 

Just did this today, The lower hose is 5/8, the upper one is 3/4

 

Fsher, if you still want to do this go to autozone/napa (the only 2 stores in Midland worthwhile) and get the heater hoses for a 97/4.0, They dont have a control valve and the hoses will be the right size/length. I can post a pic of them in my 89 if you want. (or you can look at it tomorrow when Im in town after work)