[heavyhaulerss]

Does any one have any idea where the T.P.V. is located on a 95' intl cabover? was told I may need one. the original one has never been changed. so far the truck shop nor the intl dealer can tell me where it is. shop cannot find it. 3 intl dealers & the shop said it has to have one, but dont know where it is located. and no it is not located at the back of the cab. (not refering to the dash knob park brake.)

[Blind Driver]

what is this TPV you speak of?

[pdm]

Can you follow the lines back from the glad hands? They have to come from the tractor protection valve.

[heavyhaulerss]

I have not looked extensively myself. the shop talked to a few dealers, one sais it may be behind drivers seat. not there. one said in drivers side pocket, not there. had cab jacked up, looked everywhere. had kick panels off near foot brake pedal, not there, had entire dash off, from speedo all the way to pass side area, not there. the shop had already ordered the valve, but sent it back when they could not locate the t.p.v. all the people we talked to told us where it might be or should be & had looked in all those places, nothing.


symptom.. doing brake check.. both gauges at 120 psi engine off both yellow & red knob in start pumping brake pedal air tank #1 starts dropping twice as fast as tank #2. gauge # 1 goes to 5-10 lbs. tank . #2 at this time at 60-65 lbs both knobs still in keep pumping brakes, tank 1 bottoms out, no psi in tank . tank 2 after several more pumps gets to 20 lbs then red knob pops, pump brakes a lil more to almost o psi on tank #2 & yellow pops out.. this is what prompted me to replace t.p.v. as advised. buzzer & light work o.k.

[pdm]

maybe its fastened to another valve, like the ford louisvilles were. I'm wouldn't expect replacing the tpv to change anything with your air based on your description though. The tpv keeps air from flowing out the service line to the trailer when the red button is popped.

[cdn]

follow the trailer lines back down the frame they have to go to the tvp.

[heavyhaulerss]

Originally Posted by pdm

maybe its fastened to another valve, like the ford louisvilles were. I'm wouldn't expect replacing the tpv to change anything with your air based on your description though. The tpv keeps air from flowing out the service line to the trailer when the red button is popped.

thanks.. these d.o.t inspectors have different opinion on what is supposed to work & how it is supposed to work. no violations, just a warning to get fixed. if my red button is in & truck running or off, & glad handle pulled for trailer air, red buttom pops at 40-45 or so & when it pops air does not leak it holds. when the d.o.t watched # 1 gauge drop off twice as fast & bottom out, without any one of dash breaks poppin out until only air gaige #2 got to be 20 lbs or so, said it was T.P.V.

[heavyhaulerss]

Originally Posted by cdn

follow the trailer lines back down the frame they have to go to the tvp.

thank you.. wil get my microscope & my spotlights out to locate.. i'm not replacing if that part is not defective. even if that is not the problem..still want to know where it is at though.

[pdm]

Do the guages come down together if the pedal is pumped slower? I would look for something in the air supply to the foot valve. The foot valve is fed from the primary & secondary tanks through a double check valve & sounds like tank #2 doesn't supply air as fast as number 1. The lines can be a little tricky to trace, maybe there's a kink or restricyion somewhere

[heavyhaulerss]

no matter how slow or fast I pump brakes, tank # 1 goes down faster. even when driving & braking the # 2 tank starts to come down off 120-110 only when the # 1 gauge get to 90 or so.