400 turbo w'brake no reverse

  • Thread starter Thread starter steve h
  • Start date Start date

steve h

Help. I just rebuilt a 400 turbo for my gn using a Hipster brake. Got it all done and no reverse or t-brake. With it on stands it will turn the tires in reverse but doen't have enough to move the car.
The brake will hold in 1st untill you give it some gas then it goes forward. I thought maybe i had to much travel on the rear band so i changed apply pins. No luck I air checked everything as i assembled the trans. I haven't checked line pressure yet . It does go into forward gears hard like it has plenty of pressure. Forward gears work fine. I've done 400's with tci brakes before with no problems. Any ideas? Internal problem or something fixable in car? Thanks Steve
Try neutal and hit the brake button

Is the spring on the modulator valve {spring,valve,solenoid}? Is the solenoid engaging all the way {valve connecting passages 3 and 4. etc.}? Just a couple of quick things i think of off the batt.

To ck band clearance in the car, you'll need to remove the driveshaft {or have the rear tires off the ground and trans in neutral} remove the valve body, but leave the servo together. take your air gun and burp the air gun in the band feed hole a few times quickly. If the band clearance is good, when you burp the air gun several times in a row, the drive shaft will start turning little by little with each burp of your air gun. {Crazy, but it works like a charm}

One other thing the gasket should be between the plate and case.
I checked the modulator valve and spring .Everyting there is ok. In the instructions that came with the brake it said use valve body gaskets if supplied. None were in the kit or listed with it so i didn't use any. Will stock gaskets work? Are you saying it only requires one gasket? The one on the case side? Thanks
A couple things to check, and I'm not trying to be a jerk or a smart ass. First, do you have the Hipster version that requires you to press the brake button for reverse? Second, I had a customer once who without thinking, was trying to operate a transbrake equipped car like it had a forward pattern valve body. As far as how you say the brake works, his was doing the exact same thing, because he was applying the brake in 3rd gear. When he put it in low, it worked great (this one was NOT a Hipster).

That's about all I can offer, I never use Hipster stuff. The first two I got were screwed up, and the attitude they took on the phone chapped my ass. They screwed up making them, and the valvebody locked the transmission up solid when shifted to 2nd gear. It actually threw a customers car off the jackstands in his garage. They told me I didn't know how to build a TH 400. Funny, I bolted my regular brand on and it worked perfect. I sent the valve bodies back, and about three months later, they were returned, with a half hearted apology and explanation. I just sent them right back. They may make a fine product, but I don't use them.
Good luck,
You can push the button in neutral for reverse or manually shift it. Makes no difference either way. No holding power in reverse. Yes i did have it in first. I wasn't impressed with the instructions or the that you have to grind the manual and modulator valves on a bench grinder. The last one i did with a tci brake came with new valves.
Any other ideas or anything to check. Did i get a bad brake? A 400 turbo shouldn't be this difficult.
I have also had problems with the Hipster. Thier tech help also sucks. I would return the brake and go with the TCI if that is an option. The TCI is simple and just plain works.
Did they instruct you to drive a check ball in the case in the low/reverse servo cavity? Did they instruct you to leave the inner lip seal out of the direct drum? To drill the piston? To leave a sealing ring off the center support? I'm trying to get some idea as to what they had you do. How about direct clutch clearance? Also, are you sure you have the correct piston in the direct drum? Have you got line pressure readings?

While you can build PowerGlides without valvebody gaskets, I've never seen a 400 work worth a damn without them. And transbrake valvebodies almost always require special gaskets, so don't use stock gaskets, you could cause a dangerous condition.

I was hoping Bruce could help you, as I think he may be the only guy on the board intimately familiar with the Hipster. I agree with Lonnie, if you can get rid of the Hipster, do it. Buy a Griner (the very best, but expensive), an ATI (my usual brand, I sell them), or a TCI. I've had ZERO trouble with those three.
your problem is lack of pressure in the direct drum

Why there is a lack of apply pressure in the direct drum I don't know. Drop the valve body, and air check the direct drum. If you get a good solid "thunk" apply, then the valvebody is most likely at fault, either it is bad, or it won't work without gaskets.
Call hipster and ask for a vb gasket.

Call and tell hipster you need a valve body gasket. 6packtogo is correct, it is a special gasket.

Lonnie and 6packtogo you guys crack me up. Charlie over at hipster {ATD} is a crab. Every time i talk to him he's crabby.
Re: Call hipster and ask for a vb gasket.

Originally posted by blackplague
Call and tell hipster you need a valve body gasket. 6packtogo is correct, it is a special gasket.

Lonnie and 6packtogo you guys crack me up. Charlie over at hipster {ATD} is a crab. Every time i talk to him he's crabby.

You're easily amused if Lonnie and I crack you up.

I guess dozens of pissed off customers give Charlie a reason to be grouchy.

By the way Steve, you may need to get a really large flat bastard file and use it to make sure the case is flat where the valvebody channel is.
Thanks Alan , i did all those things you mentioned and i also filled the case flat upon assembly.
I took the hipster back and traded it for a tci. I but it in and it was better but not right. Pulled the pan and the servo. Servo was stuck. After i got it out i discovered the band had jumped of the side of the apply pin. Kinda hard to see with tranny fluid dripping in your eyes.
After finding my stupid mistake i now have the tranny out to put a new band in it. Thanks to all that replied.
Lonnie i should have let you do this one for me.