Wicked coolant bypass

RAB 38

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May 8, 2007
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I put on my coolant bypass this weekend along with my twins. I have had this bypass for a few years just never got around to putting it on. I believe it is his first generation system.

Anyway, I have noticed that now it's on the truck does not get to operating temp. Seems to run around 150-160 degrees. Anybody else have this happen with their coolant bypass? I think it may be because the coolant is dumped into the thermostat housing. I have a feeling it's not going to make good heat this winter.
 
i had a truck that wouldnt get over 120 for temp and it still produced good heat, i would try changing your thermostat if anything...
 
Mine gets to operating temp but takes about 10-15miles @65mph and my heater doesnt work worth a damn but I think that the 3rd gens already have issues. Sorry no help here
 
Well it's something with the bypass cause it would get to 190 200 degrees prior to the bypass
 
Pull the relief valve and see its stuck open, its the big silver hex on the blue manifold in the middle. Any debris in the coolant system can stick it open, a flake of rust, a piece of rubber or anything. The valves aren't very forgiving.
 
Any idea about how long the install takes? I have been thinking about doing the by-pass kit myself.
 
Pull the relief valve and see its stuck open, its the big silver hex on the blue manifold in the middle. Any debris in the coolant system can stick it open, a flake of rust, a piece of rubber or anything. The valves aren't very forgiving.

Thanks for the response. I will pull it and see if there is anything in there if that's not it what would be next?
 
Any idea about how long the install takes? I have been thinking about doing the by-pass kit myself.

Average Joe taking his time shouldn't take more than 1.5 hrs unless you have twins or something making it harder to get to the plug in the head.

Thanks for the response. I will pull it and see if there is anything in there if that's not it what would be next?

It has to be bypassing from being stuck open. Either trash or failed spring in the valve itself but not very likely a failure.
 
Pull the relief valve and see its stuck open, its the big silver hex on the blue manifold in the middle. Any debris in the coolant system can stick it open, a flake of rust, a piece of rubber or anything. The valves aren't very forgiving.

Will doing so affect the calibration of the valve? I've been meaning to yank mine and change the color, just didn't want to mess up or have to recalibrate the valve.
 
RAB..


I bought one and had mine doing the same thing... It kept sticking.. No trash was found inside..

Shane sent me a new valve and it worked for a while... Then it did the same chit..


A friend and I finally figured out that those valve come apart and have a threaded cap... We were able to take it apart...

I polished and debured everything inside and then reassembled... Worked fine after that..

Also, I noticed with green coolant that it seemed to collect some weird looking slugage on the metal over time possibly causing the issue.... I switched to dex cool that doesn't have the chemical (forgot the name) that was possibly causing the reaction, and it worked fine after that...



Mine would get stuck like this


ceb8ed9f.jpg













The top cap will unscrew... You must use a vise or something with REALLY good grip to grab the cap... Then I took a large wrench and smacked it with a mallet to break the threads lose...




Just polish everything.. Mainly the little piston that moves up/down and the inside.




Unpolished pics





3d557e65.jpg


071d7557.jpg
 
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Will doing so affect the calibration of the valve? I've been meaning to yank mine and change the color, just didn't want to mess up or have to recalibrate the valve.

nothing to calibrate its simply spring tension and has no adjustment other than changing the spring.
 
Awesome, thanks for all the posts guys I'll try to take it apart tomorrow night. Let you know what I find.
I drove it for a longer trip today, about 1 1/2 hours and in traffic it got much closer to operating temp but as I would get to open road it would go back down to like 150-160 degrees.
 
When it closes properly evertime like it should, it will stay at 190-200 all time under normal driving... It should only open under heavier accelerations, then close right up again..

Good luck
 
When it closes properly evertime like it should, it will stay at 190-200 all time under normal driving... It should only open under heavier accelerations, then close right up again..

Good luck

The problem is the spring is NOT designed to regulate,its designed to POP ,if you look closely at each end it does NOT have double loops, this is the weakest point of the spring (any spring),eventually it will fail again.
 
The spring isn't the issue, particles in the coolant system is. Valve springs don't have double loops and they rarely fail. Suspension coil springs don't have them, they don't fail.
 
Once I cleaned then poished everything, along with changing coolant to dex-cool so it wouldn't react with the metal as much, it worked great..

Right up until the point when my motor blew apart.. LOL
 
Todd not sure where your logic is coming from on this one. The spring has nothing to do with the valve sticking. Its debris causing the plunger to stick. You can also note by the spec sheet that Swole posted that the valve does regulate flow according to pressure. The valve is designed as a duty cycle valve not a simple pop off style safety valve.

I believe there is a better option for the valve (I am running a few now) but the valve does regulate flow and does its job when not hampered by debris or corrosion.
 
The spring isn't the issue, particles in the coolant system is. Valve springs don't have double loops and they rarely fail. Suspension coil springs don't have them, they don't fail.

Its a simple $2.00 fix. Coil springs = Valve springs..Take a good look at the industry Standard for Valve springs.
 
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