Brakes wont hold ANY boost.

[kingots2004]

84 s-10 non power wheel cylinders but i didnt use new shoes

 

[wagon]

Were the drums new or freshly turned? How tight did you adjust the shoes? Pull the drums and look at the contact area of the shoes. How much is actually doing the braking? With new shoes, you will usually see just the very ends of the shoes making contact. They don't have the same curve as the drum. That is why you tighten them,let them wear, and tighten them again, until they grab better. If you are still having issues, then I would put on new or turned drums, and new shoes, then tighten everything up a couple of times.

 

[Chuck Leeper]

Looser verter, and a BB turbo.. Resulting in the engine getting up into a mucher higher portion of the torque curve..brakes won't hold.
AIRC, the pin on the prop valve has to be depressed when bleeding the rear brakes??
Spend a few $, and get a brake pressure gauge. That'll tell you WTF is going on. <1200 @ the M/C and you are looking at low pressure.

 

[POWERBRAKEBOB]

Hydroboost Conversion

Amazingly Enough, Yes, I Started Using The Hydroboost In The Performance Side Of Cars 20-plus Years Ago, As A Bendix Distributor. But About The H/b, It Has An Accumulator On It To Provide Enough Pressure For 3 Stops With Power Assist, With The Engine Off. Vacuum Boosters Have A Check Valve To Hold Vacuum For One Stop With Some Power Assist. As Far As Some People Feel That The Two Long Shoes On The Drum Brake Will Hold Better, Not So. Drums Brakes Are Self Energizing. The Forward (short Shoe) Is Made Of Softer Material Than The Long Shoe. It's Purpose Is To Bite The Drum, And Kick The Long Shoe Into The Drum. The Long Shoe Has The Long Wearing Material In It. It Is Harder. Using 2 Shoes With The Harder Material Will Not Bite The Drum. "burning" The Lining "in" Will Not Work. It Burns It "out". It Would Be Great To Find A Car That Uses The Hydroboost With A Line Lock To Set The Front Brakes Hard, And Add Wilwood's "lever Type" Adj Prop Valve To Set The Rear Brake Pressure Where You Want It. This Valve Would Be Mounted Near The Driver. Amazingly Enough, The 83-85 T-types Came From The Factory With "hydroboost"

 

[Boost231]

Amazingly Enough, Yes, I Started Using The Hydroboost In The Performance Side Of Cars 20-plus Years Ago, As A Bendix Distributor. But About The H/b, It Has An Accumulator On It To Provide Enough Pressure For 3 Stops With Power Assist, With The Engine Off. Vacuum Boosters Have A Check Valve To Hold Vacuum For One Stop With Some Power Assist. As Far As Some People Feel That The Two Long Shoes On The Drum Brake Will Hold Better, Not So. Drums Brakes Are Self Energizing. The Forward (short Shoe) Is Made Of Softer Material Than The Long Shoe. It's Purpose Is To Bite The Drum, And Kick The Long Shoe Into The Drum. The Long Shoe Has The Long Wearing Material In It. It Is Harder. Using 2 Shoes With The Harder Material Will Not Bite The Drum. "burning" The Lining "in" Will Not Work. It Burns It "out". It Would Be Great To Find A Car That Uses The Hydroboost With A Line Lock To Set The Front Brakes Hard, And Add Wilwood's "lever Type" Adj Prop Valve To Set The Rear Brake Pressure Where You Want It. This Valve Would Be Mounted Near The Driver. Amazingly Enough, The 83-85 T-types Came From The Factory With "hydroboost"

very nice. im glad i have hydroboost.

 

[TURBOGTA1]

Amazingly Enough, Yes, I Started Using The Hydroboost In The Performance Side Of Cars 20-plus Years Ago, As A Bendix Distributor. But About The H/b, It Has An Accumulator On It To Provide Enough Pressure For 3 Stops With Power Assist, With The Engine Off. Vacuum Boosters Have A Check Valve To Hold Vacuum For One Stop With Some Power Assist. As Far As Some People Feel That The Two Long Shoes On The Drum Brake Will Hold Better, Not So. Drums Brakes Are Self Energizing. The Forward (short Shoe) Is Made Of Softer Material Than The Long Shoe. It's Purpose Is To Bite The Drum, And Kick The Long Shoe Into The Drum. The Long Shoe Has The Long Wearing Material In It. It Is Harder. Using 2 Shoes With The Harder Material Will Not Bite The Drum. "burning" The Lining "in" Will Not Work. It Burns It "out". It Would Be Great To Find A Car That Uses The Hydroboost With A Line Lock To Set The Front Brakes Hard, And Add Wilwood's "lever Type" Adj Prop Valve To Set The Rear Brake Pressure Where You Want It. This Valve Would Be Mounted Near The Driver. Amazingly Enough, The 83-85 T-types Came From The Factory With "hydroboost"

Bob, do you sell the Hydo-boost conversion for the 86-87. If so, can you send details of kit, and any other parts required to do the install. Turbogta@aol.com Mike

 

[8AV8]

Amazingly Enough, Yes, I Started Using The Hydroboost In The Performance Side Of Cars 20-plus Years Ago, As A Bendix Distributor. But About The H/b, It Has An Accumulator On It To Provide Enough Pressure For 3 Stops With Power Assist, With The Engine Off. Vacuum Boosters Have A Check Valve To Hold Vacuum For One Stop With Some Power Assist. As Far As Some People Feel That The Two Long Shoes On The Drum Brake Will Hold Better, Not So. Drums Brakes Are Self Energizing. The Forward (short Shoe) Is Made Of Softer Material Than The Long Shoe. It's Purpose Is To Bite The Drum, And Kick The Long Shoe Into The Drum. The Long Shoe Has The Long Wearing Material In It. It Is Harder. Using 2 Shoes With The Harder Material Will Not Bite The Drum. "burning" The Lining "in" Will Not Work. It Burns It "out". It Would Be Great To Find A Car That Uses The Hydroboost With A Line Lock To Set The Front Brakes Hard, And Add Wilwood's "lever Type" Adj Prop Valve To Set The Rear Brake Pressure Where You Want It. This Valve Would Be Mounted Near The Driver. Amazingly Enough, The 83-85 T-types Came From The Factory With "hydroboost"

So the material in the short shoe and long shoe is different on all brands of brake shoes?


And having two long shoes will prevent the brakes from "kicking" the rear long shoe?


Just trying to understand...

 

[POWERBRAKEBOB]

Lining Material

Yes. The Shorter Shoe Has A Higher Friction To Energize The Rear Shoe. The Rear Shoes Takes The Brunt Of The Heat And The Wear. It Is Harder Material And Longer In Length. Putting 2 Shoes Of A Harder Material Does Not Increase Friction, It Only Increases The Usable Life. In Disc Brakes, Oddly Enough, They Used To Call Them "pucks". They Were Round And Small. The Smaller They Are, The Deeper They Can Push Into The Rotor. "point Pressure" So To Speak. They "pinch" The Rotor. The Longer The Pad, The Longer They Last, But The Point Pressure Goes Down. Most People Think That A Longer Pad Or Shoe Will Have More Friction. A Little, But The Loss Of Pressure Against The Rotor Or Drum Decreases The Locking Power, As The Pad Lengthens. It Is Kind Of Like The Pressure A Ladie's High Heel Can Put Into A Surface, Compared To A Wide Heel.

 

[TurboBob]

Lets get back to the changes that caused the issue.

A restalled D5 has piss-poor torque multiplication (~1.4 ?). This is because the guts are bent/machined to let it stall higher at the line.

A good 10" converter has really good multiplication (~ 2.5 ?), plus you are further up on the powerband.

So if you are making about 150 ft-lbs at 0 psi, the stock converter was putting out 210 ft-lbs, the new converter is putting out 375 ft-lbs !!!!

So you are overpowering your rear brakes.

That said, my car is also killing the rear brakes because of my new converter, so I am anxiously waiting on the answers in this thread.

Bob

 

[chopped39]

WOW! I guess I hit a nerve. Apparently I wasn’t very clear. The stalling problem wasn’t tune, it was programming in the chip. I’m glad your cars don’t stall, but I do know of a few that do and I’ve been driving these cars for a long time too. Before you get your undies in a bunch again, all I was doing was pointing out a potential down side of the system, not saying it’s no good. Personally I like the power master system but I haven’t had any problems other than accumulator failures but I know some people can’t stand it – I can’t accept that.
I do agree that bandaiding the loss of rear braking power with the hydro boost system isn’t a good idea. Installing for it’s own merits is a different story.

Throw a rod out of the motor at 125 mph and tell me how that hydroboost works then. And the power master ha thats why my car is being repaired.pos went out right when guy threw a u turn in front of me while i was driving 40 mph. never had a problem until then. went with vacuum conversion been around for a long time. Probably why pontiac went with it on the tta. At least you have something when car dies or starts to stall . you can even put eletric vacuum pump if you want. That is just my opinion. I just dont like when there is something that is in control of my brakes let alone steering and brakes I would say the hydraboost is alot better than the pos power master . Not cheap though. just my 2cents

 

[pacecarta]

not to get too complicated and discuss stall and whatnot ....we are talking about inabilty to hold the rear wheels
a very common failure on 20yr old cars is the rear brake hose , went through this a couple times only to end up at the hose (which i hate doing because it usually means replacing old steel lines that twist up )
the hose is cheap (about 15bucks) and something to look into
this past week my s10 (same brake setup ) failed inspection , brake test showed zero brake at rear wheels , bled the heck out of it (vacuum bleeder) , replaced everything (m/c, prop valve, shoes ) adjusted, bled and still like before only enough to hold the tires still in drive , wouldnt hold anything under throttle, had dont the cylinders two years ago and they werent leaking so only thing left was that hose by the pumpkin
replaced the rear hose (and bled rear cylinders again)and that was the trick
i can stand on the throttle and the wheels wont budge and thats with wheels off the ground.

if your going to be bleeding anyway might as well replace the front hoses too , they run about 12bucks each and the pedal should improve overall

 

[JimP]

I discovered the same problem when I changed to a new higher stall converter. I have a PATS 10 inch lock up, it does stall at 3,400 rpm's. On my restalled D5, I was able to hold 6 lbs of boost. With the Pat's I see 3,000 r.p.m and zero boost on the guage, then tires begin to spin.

I am due for rear brakes and I have since stock piled 85 S-10 manual wheel cylinders, very soft large brake shoes and stainless steel brake flex hoses. I am certain this will cure my issues. I guess with the greater torque multiplication of the PATS converter, the brakes can't hold the tires before you hit boost.

Don't get me wrong, I love this coverter, it works great with my TE-61. I haze the E/T streets from a roll at any speed less than 35 mph. The car felt dead for the first 100 feet with the D5 restalled.

Let us know how you make out.