D6H park brake

[jook24]

My 1997 D6H when i put the park brake on and leave it idle i have to turn turn the shifter lever forward and backward then it will move.If i leave it off it will move right away other than that it shifts good and runs at 190 to 195.third gear is locked out tho.

 

[kshansen]

As I often say a full serial number or at the very least a serial number prefix will improve your chance of an answer. Just a quick look on SIS shows two dozen different prefixes for a "D6H". Sure many of them are probably the same basic design but not knowing limits what one could find on possible causes.

 

[jook24]

5hf05925

 

[kshansen]

Hope someone familiar with this machine chimes in on the question.

From what I see the parking brake of this machine is actually the same brake as what I would call the service brake. Reading the Systems Operation manual I see that the brakes on this machine work somewhat the opposite to what one might expect. What I saying is you send pressure to the brake to release it and vent off the pressure to apply the brakes. There is a belleville spring in the brake that applies pressure to the brake disks to stop the machine.

There is a valve that the "parking brake" linkage controls and in the "off position" should be sending oil pressure to the brake to release it.

Wish I could be of more help.

 

[jook24]

It's a start sure it's nothing serious as the transmission and torque were done before i bought it by cat dealer 2500hrs ago

 

[Nige]

I’m trying to get my head around the symptoms you are describing. Is the following explanation correct..?
1. If you apply the parking brake, shut the engine down and then later start it up again, the parking brake releases as soon as you move the park brake control to the released position.
2. If you apply the parking brake without shutting the engine down, the brake applies correctly but will not release unless you engage the transmission into fwd/rev at which point the brake will release.

 

[jook24]

I haven't tried applying park brake and shut engine down and restart but when left idling and apply park brake twist lever forward and reverse a few times then it will move and brake releases.

 

[DMiller]

Solenoid control sounds to be hanging/sticking for brake release.

 

[jook24]

Keep thanks will look into that

 

[truecountry]

Now if I'm reading this right you have to go forward gear then reverse then back to get it to move engine running park brake applied then park brake off forward reverse cycle to move ..change filter see whats in it metal or other things
that's if that's i'm correct in your post

 

[jook24]

park brake is applied with engine running then release park brake then turn shift lever forward then reverse a couple of times and it kicks into gear.If park brake is off it does not do it.got all service papers with cat when i purchased it had15410 hrs.when i bought it had complete service done with oil samples all good by previous owner.it now has 15800hrs. and trans. and torque were redone by cat dealer at 14473 i got the papers with the cat when i bought it.Not saying they could miss something the owner was right up on servicing his equipment he was retiring had a large fleet.

 

[HSV127]

I had a similar problem on my D6H 4YF-00444. Park brake wouldn't always release and brakes were randomly coming on while driving, turned out to be the park brake linkage needing adjustment (wasn't quite opening the park brake valve properly), pressure tested the brakes while in there, all sweet now.

 

[Nige]

There's plenty of room for slop in the rods 2 & 3 plus all the associated clevises & pivot points.
Clean & lubricate the linkage as a first step..?