Can elevation affect clutch hydraulics?

[RT395]

Three times since May I have been up at high elevations and noticed that my clutch is failing only to have it return to perfect working order when I return to sea level.

At first I thought it was heat related because I was pulling my 8k bumper trailer up the passes and while I’m sure heat is a contributing factor, even after cooling overnight the problem persists until I return to lower elevations.

This past weekend it got so bad that I could not get the truck into low gear at all.

At no time have I ever detected the clutch slipping - I just can’t disengage it - the pedal develops an inch and a half of play at the top and no longer feels solid.

The only theory I have so far is that an air bubble in the hydraulic system which has little or no effect at sea level is expanding when I take the truck up to 9,000’ elevation?

Has anyone ever experienced this issue? Or does anyone have a different theory as to what the problem might be?

I have checked for leaks and found nothing - I'm getting ready to try and bleed the system which I understand is possible even though it does not have a bleed screw. (more of a burping process)

(My truck is all stock and has only 45k on the odometer)

 

[nukegm]

rt395 - my guess is yes elevation can affect any air in your clutch system. higher up = less pressure, therefore the air in your system would expand. ( however im just a carpenter ). i base this on bags of food i buy down the hill are on the verge of explosion when i get home.

my 2500 g56 was in shop for 29 days. clutch hydraulic failed, 3 times. as a coincidence, the truck became un - driveable the higher up i went on my way home.

i work at 5000 feet but live at almost 10,000

the dealer found the first replacement was bad out of the box, the second one had an " internal leak "etc...

at the time of my failure, the truck had about 7000 miles on it.

good luck, and cheers comrade!

 

[GCroyle]

Air is not allowed in clutch hydro's. Period.

Easy to TEST your hydro's to prove bled or contains air.

Remove slave cyl from trans. Remove push rod and dust boot.
Bolt up a steering wheel puller to front of slave cyl, finger tight.
Turn screw in just enough to nicely BLOCK the slave cyl piston from moving.
Push on clutch pedal with finger tips only.
Measure how far clutch master cyl push rod moves before you feel hard pedal and creating PSI.

1/8"or less GOOD

Anything more than that, you compressed air first, then started making PSI.

With or without a bleed screw the Dodge system CAN be burped.

Only good reason to replace parts is visible weeping leaking or you just want to spend $$$

Gary

 

[nukegm]

Air is not allowed in clutch hydro's. Period.

Easy to TEST your hydro's to prove bled or contains air.

Remove slave cyl from trans. Remove push rod and dust boot.
Bolt up a steering wheel puller to front of slave cyl, finger tight.
Turn screw in just enough to nicely BLOCK the slave cyl piston from moving.
Push on clutch pedal with finger tips only.
Measure how far clutch master cyl push rod moves before you feel hard pedal and creating PSI.

1/8"or less GOOD

Anything more than that, you compressed air first, then started making PSI.

With or without a bleed screw the Dodge system CAN be burped.

Only good reason to replace parts is visible weeping leaking or you just want to spend $$$

Gary

hey comrade gary - so when all the fluid leaked out of my clutch hydraulics, my guess is that air took its place - right? just throwin that out there. cheers!

 

[RT395]

Thanks for the responses.

Nukegm - 29 days in the shop is crazy!

Gary - I'll try the test you suggested before I burp the system.

I'll be watching closely to see if any air bubbles actually burp from the reservoir.

I suppose its possible that a negligible amount of air in the system that is unnoticed at sea level could expand enough in 9,000' of elevation gain to essentially disable the truck. Imagine if that happened to the brakes!

 

[nukegm]

Thanks for the responses.

Nukegm - 29 days in the shop is crazy!

Gary - I'll try the test you suggested before I burp the system.

I'll be watching closely to see if any air bubbles actually burp from the reservoir.

I suppose its possible that a negligible amount of air in the system that is unnoticed at sea level could expand enough in 9,000' of elevation gain to essentially disable the truck. Imagine if that happened to the brakes!

f y i , ram stepped up and re paid me for 2 flat bed trips , and for my monthly payment, which is not much, but out of principle i asked them for it - due to the almost month at the dealer. keep us posted. cheers!