bad brake pedal, help with diagnosis please

[Toby_Goodmk]

Here is what I was told. The speed of the fluid, if not slowed down will cause a spinning and aeration if you have everything sealed up. This was in my case, i replaced the orifice and the noise went away. So problem solved with aeration.

As for the bad pedal, I have tried quite a few "tests" today. I switched the return lines as Dr Boost stated, same ordeal. Same pedal. I re bled today two more times and made sure my basis was covered with air in the lines. Same pedal. I adjusted the rear brakes to a real nice amount, same pedal. I took the belt off...cleaned it...let me tell you why. When running alum pulleys the belt gets a layer of alum from riding the power steering pump pulley and idler. So that made a little difference, not much....nearly the same pedal. Drove the car today for a bit. thank God it was warm....to try to purge any bubbles from the steering circuit....then re bled the lines again...same pedal. I also took the return from the HB and plugged off the T as I described above. I had my kid apply brakes as i held the return into the reservoir. I had a little stream of fluid on pressing the brake pedal, then a spurt when letting off the brake... then apply again....a few drips....little if no fluid,,,, then a spurt again of fluid when letting off the brakes. I think this is normal so I am baffled once again. WIll know more when I call Jim and Hydratech on Monday with my test results. Upon driving the car this is what I experienced that makes me wonder if the HB if getting enough flow. When braking...and turning slightly the brakes seem to lock up and brake better. Its like the HB gets an additional amount of hydraulic pressure that allows the piston to push the master cylinder more since the power steering circuit is pushing fluid.

All I know, this is one hell of a diagnosis....learning quite a bit here.

 

[Toby_Goodmk]

next symptom, pushing down on brake pedal and the steering wheel is damn near impossible to turn....increase RPM, and doesnt make a difference. THis is being done while sitting in the garage not moving at all. Let off brake, steering ok.

 

[TexasT]

That h-b unit must take a lot of volume if it it taking it all and not leaving any to run the pwr steering.

 

[Hot Air]

One fundamental question....do you have a reverse rotation power steering pump? Most power steering pumps come with pulleys that are grooved to mate with the grooves on the serpentine belt. If you will notice, our pump pulleys are smooth which means they are designed to run on the back of the serpentine belt. That makes it a "reverse-rotation" pump. Be SURE to tell anyone when you are ordering a PS pump that little tidbit of info or you WILL get the wrong pump. A lot of "performance" books incorrectly indicate that the Corvette PS pump will work. NO!!!
Conrad

 

[Jerryl]

So, are both of y'all using a factory hb unit? What master cylinder? Powermaster pedal?

I'm not sure how the reservoir has bubbles if air isn't being introduced. Something is causing the fluid to be agitated. I do see the thought about the fluid running into itself and being agitated.

Stock reman 84 HB with stock lines.

Sent from my SM-N910H using Tapatalk

 

[Toby_Goodmk]

That h-b unit must take a lot of volume if it it taking it all and not leaving any to run the pwr steering.

Going to be placing a call with Jim at Hydratech,.....again....thank God for his kindness. Ill be giving him my results as well as a couple videos that I shot, which will be posted here in a bit. But to talk volume needed by the pump.....dont think so, I think (before speaking with Jim) that the spool valve is not channeling the flow correctly. We will see.

 

[Toby_Goodmk]

One fundamental question....do you have a reverse rotation power steering pump? Most power steering pumps come with pulleys that are grooved to mate with the grooves on the serpentine belt. If you will notice, our pump pulleys are smooth which means they are designed to run on the back of the serpentine belt. That makes it a "reverse-rotation" pump. Be SURE to tell anyone when you are ordering a PS pump that little tidbit of info or you WILL get the wrong pump. A lot of "performance" books incorrectly indicate that the Corvette PS pump will work. NO!!!
Conrad

Conrad,

WHen I call Jones performance I will make sure to discuss with them on reverse rotation. I do have a reverse rotation pump ( i believe) however I cannot rule ANYTHING out of the normal....like the Bengals on Saturday night But wouldnt the power steering not work at all if I happened to get ahold of a clock wise flow pump from Cardone?

 

[Toby_Goodmk]

Stock reman 84 HB with stock lines.

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Thought we needed to use a cast iron unit with our HB?

 

[Hot Air]

I think it will work a little!

 

[Toby_Goodmk]

Waiting on the answer from Hydratech about clockwise rotation pumps and how they react.

Jim thinks the issues are power steering related. Also.....using the lucas power steering fluid with conditioner is too thick. I dont believe it myself, but he had another customer with the same issue. Says to use Redline or Royal purple syn power steering fluid. Another thing to check is the relief valve under the orifice. If the valve does not move freely it can cause same issues. Need to remove it and inspect for highly polished areas around the lands, this would indicate a hang up of fluid flow by the increased friction in the bore.

 

[Nick Micale]

It could be as simple the wrong belt, and it is too long?

I have gone through the 86-87 GN belt issue as different brands are not all the same size either.

The original stock belt and GM initial replacement is 1618 mm, the next batch of GN belts are 1622 and some ofthe current belts are longer still, up to 1642

The Gates belt no. K060630 is 1618 mm and may be the solution, as a customer had the same issue a couple months ago, and he went away happy!

 

[Toby_Goodmk]

Nick, understood and will study my belt number. I feel it is correct, however I am not entirely sure. It is a part number 6PK1615 Dayco

 

[Toby_Goodmk]

Going to get a new belt tonight, happens to be the belt for an 02 Chrysler Concorde with a 2.7

 

[Toby_Goodmk]

clockwise rotation on pumps will not permit any steering efforts, fyi

Will change belts, go to Royal Purple steering fluid and check the valving.... See where we stand.

 

[Toby_Goodmk]

Well folks...here is the 411. I am about as embarrassed as our beloved Cincinnati Bungles, however if we don't make mistakes one can never learn...unlike the Bengals. Anyhoo when I converted over to AN fittings I had the lines at the head switched. The pressure line going to the power steering pump hooks to the side of the HB closest to engine. Line closest to fender attaches to the steering gear. I took Nicks advice and used the belt from a 2.7 chrysler and it fits tight...the Dayco 5060630 is 16$ at advance and is very quiet on the pulleys. It rides with a better amount of tension on the idler. So...consider this case closed....just if you cross your lines doing a AN conversion make sure they are routed correct!!

 

[Jerryl]

Well . . . Hot dangit. Guess i will need to hurry and start this. Can you post a pic of the routings?
Man not sure how to thank you for getting to the bottom of this.

Thinking about it . .
Not sure if my factory lines can be installed backwards. [emoji27]

 

[Toby_Goodmk]

Well . . . Hot dangit. Guess i will need to hurry and start this. Can you post a pic of the routings?
Man not sure how to thank you for getting to the bottom of this.

Thinking about it . .
Not sure if my factory lines can be installed backwards. [emoji27]

yea, you cannot switch the lines on the factory setup. Ill be posting a couple videos of what a pedal looks like and presses down with the lines switched as well as a video of the line routing.

 

[Toby_Goodmk]

here is the bad brake pedal koeo and at start up how much it drops with the lines switched

 

[Toby_Goodmk]

and here is the routing.

 

[Jerryl]

More info along the same lines.
Never got the brakes to work right. Power assist (HYDROBOOST) section appears fine.

Ended up having 4 bad master cylinders in a row.
How? Don't know.
Confirmed? After bench bleeding each, I plugged the ports at MC on the car with some metal fittings I made. Engine off, pedal starts out hard but keeps dropping about 1/2 way down.

Waiting for a MC from Wilwood.

Here is something intetesting:
Most available MCs have the rear brakes going to the primary circuit. I firmly believe this is absolutely incorrect and Buick had it right on the PM units. You want the front to apply first or the car can lock the rear tires and become unstable.

The Wilwood MC to use as a direct swap when going from PM to HB is from a Chrysler. Not the prettiest or sexiest looking thing but it's all thats available.

Hope this helps.

Edit.
The Dodge master cylinder did not fit. I am returning it and just wanted to share because that was bad info. Back to square one