A fellow racer is having an issue with his adjustable trans brake button. He asked me because I do mostly GM, PG, 350 and 400's. I do some old school ford and mopars, but I stay away from the electronic transmissions. His problem is the output wire from the button to the valve body is melting the solder off the connection on the button, occasionally. Weird thing number one: it doesnt blow the fuse on the power wire going to the button. Weird thing number two: It happens, again, just occasionaly, when he goes to back up. Weird thing number three: if he just uses it as a trans brake, it works fine, as does the transmission. My first thought was the bulkhead fitting for the wire to the valve body on the back of the case. I have discounted that for the most part because if he doesnt put it in reverse, its ok. I havent got into it yet because he hasnt had time to bring it to me and we have just checked it at the track. I just cannot visualize anything in the reverse system that could be doing such a strange thing. Anyone have any suggestions? I dont want to spend a thousand dollars of his money on a new valve body if there is another solution.

Just an off the cuff guess...

The circuit that is used to back up is somehow not grounded properly and the 12volt + feed is seeking a ground.

High resistance will create high heat.....

Quickest way to band aid, run the +12 to transbrake through a relay (20/30 amp rated) and fuse it for 20 amp on the feed side.

I was thinking a ground short also, but, hes on the trans brake longer at stage than he is backing out of the pit. The relay is an good idea, I have a box of them I use for fans, etc. He gets so spooked sometimes that when he has to back out of the beams for whatever reason, oil down, car stopped on the track, etc, he will shut off and have the track crew push him back to the water. It only happens maybe two or three times out of ten, and only when in reverse. That is the part that is so mind boggling.

How about wire in a separate button for reverse and use a heavy duty button that uses screw terminals

few things come to mind where it the trans getting a ground is it grounded with its own wire?
second does the car have reverse lights if so may be look into that circuit.

top, he ran a steering wheel button for years for the trans brake, then decided to try a adjustable button mounted on a stand next to the shifter. still has the button coiled up and zip tied under the dash. we did try using the old button which is teed together with the adjustable, same result. camaro, no back up lights,and no seperate ground. just one wire from the button to the transmission, grounded internally through the transmission. Now that you mentioned it, I wonder if the chassis ground is loose between the frame and the powertrain.But, you would think that would just cause an open circuit and not a ground fault.

Car is not grounded well enough.

Phil, that is going to the top of the todo list.Thanks.

quote:

Originally posted by camaro77:
few things come to mind where it the trans getting a ground is it grounded with its own wire?
second does the car have reverse lights if so may be look into that circuit.

Reverse lights? That is a very good thought. The solenoid itself is grounded same way in reverse or low gear. That solenoid SHOULD draw same power to engage in forward or reverse. But if it has reverse lights that could be a little higher amp draw though not much. Strange but worth checking out.

One thing I have always wondered about on the transbrake they say run a minimum of 12 gauge wire to solenoid yet coming out of the solenoid they have a very wimpy like 24 gauge wire? Seems like if the require a 12 gauge to the solenoid it would have at least that large of wire going into it.

As mentioned earlier good grounds are important.

Curly, when I do 727/904's, it is basically a "refresh", discs, plates,soft parts. the closest I get to the valve body is the r&r of it. When you said it grounds in low and reverse, did you mean ONLY in low and reverse, in other words if I put the trans in 2nd or 3rd and push the button the brake wont energize unlike the GMs' that will work anytime the button is pushed? I am completely illiterate on Chrysler valve bodies.

I do not know about the 727 / 904 I think the way they operate is similar on all and I would troubleshoot it same.

Can you check amp draw in low and reverse? Car would not need to be running for that and see if there is any difference. Then if it is the same check it again running. If so trace that back to find possible problem. If the amp draw is higher when it is not running then I would think it has to be an electrical supply issue on the hot side.

I would also consider a fuse inline temporary until you get issue resolved. A fuse is cheaper and easier than replacing solenoids.

quote:

Originally posted by Curly1:
I do not know about the 727 / 904

of course you don't but feel compelled to reply, offering opinion rather than 1st hand experience and knowledge which is typical of many of your replies!

Thanks for the replies and suggestions. I am going to try and get his car over here this weekend and start checking things out, and implementing the ideas. That is if hurricane Hillary doesnt move 300 miles inland.

Do you know who's valve body it is by chance?

No, not yet. I havent dropped the pan yet, was going to this weekend but hurricane hillary seems to want to change my plans. We either get no rain or it floods, there is no in between, and it is doing the latter right now. If I can just get the car over here I can get it indoors and try to figure out what it is doing.

quote:

Originally posted by 1320racer:

quote:

Originally posted by Curly1:
I do not know about the 727 / 904

of course you don't but feel compelled to reply, offering opinion rather than 1st hand experience and knowledge which is typical of many of your replies!

As usual little Ediot has no solutions here only cheap insults to others. Every single post you make is to brag on yourself like you are important. (You are not) or to blast others. Severe case of Small Man Syndrome.

Says the clueless lying that has offered no solutions to the OP yet felt compelled to reply

quote:

Originally posted by Curly1:
I do not know about the 727 / 904

because he’s desperate to feel relevant just as he’s desperate to have a girlfriend so he pays prostitues by the hour to be that!

Same clueless idiot that claimed to own a race car and trailer he does not and fried the guy’s engine he tried to “tune”

quote:

Originally posted by qtrrcr:
Thanks for the replies and suggestions. I am going to try and get his car over here this weekend and start checking things out, and implementing the ideas. That is if hurricane Hillary doesnt move 300 miles inland.

quote:

Originally posted by 1320racer:
Says the clueless lying that has offered no solutions to the OP yet felt compelled to reply

Says our resident special needs child that has offered nothing to the OP. YOUR sole reason for your responses was to engage Curly.

The OP, thanked everyone for the "replies and suggestions." including Curly!

2BKING

Mr King try not to let Little Queen bother you. He has Brain Damage and Small Man Syndrome.