Hey guys, finally getting to the point I can stop taking things apart and start putting them together. One of the first subassemblies is the Hydroboost system. I have the booster, but I am missing a part. There aparently is supposed to be a Pin protruding from the booster to push in the piston on the MC, I ain't got one. I copied this pic from someones thread. The Red Circle indicates the part I need. Any Ideas where I can aquire one of these? I guess I could make one, If I knew what it looked like..


Thanks Guys

 

This is just an idea, but for lack of anything better.......

Most boosters that are sold come with two rods, one short and one long. You may be able to go to a brake shop and see if they happen to have one laying around. Might even let you have it for free. Worst case is that they charge you a couple bucks for something they probably would just toss.

I tossed my extra.

 

The problem I think you are going to encounter is that that pin is not supposed to be removable. If it's missing, it was probably broken out.

The only place to get one would be from another Hydro unit. I can maybe find you another one if you tell me what year and make your Hydro came from.

 

I have no idea what it came from

Somewhere I had a drawing of what this thing looks like inside, mechanical drawing. Anyone got a copy?

 

Been looking at the unit, it is not broken, the pin is just missing. There is a piston in there with a dimple in it to accept the pin, so it looks like I just need to figure out how long it should be and make one.

I could still use that drawing if anyone has one.

 

It's 230, am now, if you want, tmrw morning I can go out and measure my pin...gotta pull the m/cyl off to do so just 2 bolts...apparently that pin is supposed to just pull out, it must have a gasket around it for dust/something to stop it from falling out, maybe it was a bit loose??

I look in the AM....

 

Hey Gene, that would be great, save me from having to do the trial and error thing. The pin rides in a support in the snout end of the HB unit and in the detent in the piston on eht back side.
I appreciate the help, length and diameter if you don't mind, but don't put yourself out.

thanks

 

6', sorry man, I got it apart, and it's held in there spring loaded against a starwheel type thingy pressed in place I grab that shaft with pliars and it wants to spring right back in place....I hear a spring sort of ring slightly when that happens.....with no clue of a diagram, I donwanna pull it apart much further.....it's about 3/8 diameter though bullet round on the end....protrudes from the star wheel about 1/2 inch....

gee this took just hours and hours to do too.....











one minit 30 seconds.....I"l send a bill.....

 

LOL, Thanks Gene

 

OK, talking to the Hydratech guys, the pin should be 3.125" long and can be fabbed from a piece of 3/8" cold roll, with no special hardning needed. The HB unit itself comes in 2 versions of power piston, Dimpled like mine and concaved. There is a groove machined on the pin close to the piston end that will retain a Teflon disk that is merely a guide for the pin to keep it centered on the piston. They also say the Star washer can be easily poped out so the inner bore can be cleaned and the pin/retainer installed. Looks like it will be easy. I waiting on a call back from Precision Rebuilders for a Flat mounting plate and a replacement mount nut, the one that came with my unit was Peened to lock it on the unit.
I'll let ya know how it comes out

 

I took one apart last winter, and it did not have a pin that was easy to remove. I think it was a design that they didn't want serviced. The mounting plate wouldn't come off, and the pic wouldn't come out. It was a junk unit anyway. With the correct ones it's so much easier.

 

OK, here is how that works:
The large mount nut was Peened when it was assembled, that means they put a Punch on the edge next to the threads and smaked it with a hammer to distort the threads, that effectively locks the threads. I think I could come up with a better way, but certainly not as cheap as they did it.
The nut WILL come off with a large pair of channel locks, carefull it bites.
The pin will come out, grab it with vice grips and pull, it is retained by a plastic disk snapped into a groove at the end of the steel pin, just pull, it will come out, it is just a guide to keep the pin centered on the Power Piston.
If your missing a pin, it is easy to fab, 3/8" cpld roll stee, approx 3.125 long, round on both ends, use a triangle file to file a small groove 1/2" from one end for the plastic disk to snap into.
The star washer in the snout of the unit will pop out with a pair of needle nose pliars, be carefull, the spring will want to pop out.
use a small wire brush to lean up the bore inside, clean the spring. Place the plastic disk on the pin, slide the pin disk end first into the snout of the HB unit. Install the spring over the pin. Install the star washer over the pin and into the snout.
When fully assembled the pin should just contact the piston in the back of the Master Cylindar.
Recommended install method is different than the old stuff came out. You will need 4 3/8" studs installed from the inside thru the firewall, Much easire to deal with.
the mountong plate should be flat. the mounting hole for the HB unit is dead center of the bolt hole pattern. The bolt hole pattern is 3.5" x 3.5", The holes are .4"
I'll be fabbing a pin and plate tomorrow evening, pics to follow