Author Topic: Hydroboost Braking System  (Read 114707 times)

Offline DaveVA78Chieftain

  • 14 year member
  • *
  • Posts: 3555
  • Member since: 2003
  • I own: a Motor Home
  • Year: 1978
  • Make: Winnebago
  • Model: Chieftain
  • Chassis: Dodge M400
  • Engine: 440-3
Hydroboost Braking System
« on: March 15, 2014, 06:59 PM »

Offline Stripe

  • *
  • Posts: 1652
  • That which does not kill us, missed...
  • Member since: 2012
  • I own: a Motor Home
  • Year: 1984
  • Make: Holiday Rambler
  • Model: Imperial-28 28'
  • Chassis: Chevy P30
  • Engine: 454
Re: Hydroboost Braking System
« Reply #1 on: March 15, 2014, 11:58 PM »
 ??? wow ???
Fredric,
Captain of the Ground Ship "Aluminum Goose"
28' Holiday Rambler Imperial 28

Offline circleD

  • *
  • Posts: 496
  • Any day you wake up is a great day
  • Member since: 2013
  • I own: a Motor Home
  • Year: 1984
  • Make: Holiday Rambler
  • Model: Imperial 33
  • Chassis: p30
  • Engine: 454
Re: Hydroboost Braking System
« Reply #2 on: March 24, 2014, 05:16 PM »
Just an FYI for everyone. I've had issues with the brake pedal going to floor and not stopping hardly. I've bled/flushed the 4 disc brakes with no better stopping power. Today I bled the power steering pump per the instructions and I can stop better now! If I double pump them its better. I'll have to bled them again later. Also, I disconnected the tag axle vacuum booster at the rear of the motor and now my vacuum gauge stays at 16 psi when I hit the brakes ( that's a later project). But if you read all of the pages in the manual it WILL fix a lot of stuff.

Offline Stripe

  • *
  • Posts: 1652
  • That which does not kill us, missed...
  • Member since: 2012
  • I own: a Motor Home
  • Year: 1984
  • Make: Holiday Rambler
  • Model: Imperial-28 28'
  • Chassis: Chevy P30
  • Engine: 454
Re: Hydroboost Braking System
« Reply #3 on: March 24, 2014, 06:45 PM »
Indeed..   Hm?
Fredric,
Captain of the Ground Ship "Aluminum Goose"
28' Holiday Rambler Imperial 28

Offline ramit

  • *
  • Posts: 56
  • I own: a Motor Home
  • Year: 1984
  • Make: Itasca
  • Model: Sunflyer
  • Chassis: GMC
  • Engine: 454
Re: Hydroboost Braking System
« Reply #4 on: March 24, 2014, 07:03 PM »
 :)ThmbUp

Offline cncsparky

  • *
  • Posts: 348
  • Member since: 2012
  • Year: 1988
  • Make: Sportscoach
  • Model: Cross Country
  • Chassis: Chevy
  • Engine: 454
Re: Hydroboost Braking System
« Reply #5 on: March 26, 2014, 09:15 PM »
CircleD, any idea how much power steering fluid is needed to dump and refill the hydroboost system?
-Tom

Offline circleD

  • *
  • Posts: 496
  • Any day you wake up is a great day
  • Member since: 2013
  • I own: a Motor Home
  • Year: 1984
  • Make: Holiday Rambler
  • Model: Imperial 33
  • Chassis: p30
  • Engine: 454
Re: Hydroboost Braking System
« Reply #6 on: March 26, 2014, 09:35 PM »
My rig sat for 2 years and it was (full) I haven't driven it but maybe a mile total for safety reasons. After I did what i did in original post it took 1.3 small bottles to get it over the full mark. I think there's an amount in one of the manuals on here from the factory. But I would say 3 small bottles at leastif drained.
DAVE will know  ;).  He's my hereo :D

Offline DaveVA78Chieftain

  • 14 year member
  • *
  • Posts: 3555
  • Member since: 2003
  • I own: a Motor Home
  • Year: 1978
  • Make: Winnebago
  • Model: Chieftain
  • Chassis: Dodge M400
  • Engine: 440-3
Re: Hydroboost Braking System
« Reply #7 on: March 28, 2014, 11:30 AM »
Sorry, while they provide the information for most everything else, neither the Service Manual nor the Service Guide provide the power steering system capacity.  I looked at both the capacities table and Power Steering sections.

Dave

Offline eXodus

  • *
  • Posts: 366
  • Member since: 2014
  • I own: a Motor Home
  • Year: 1994
  • Make: Itasca
  • Model: Sunrise 29RQ
  • Chassis: Chevy P30
  • Engine: 454
Re: Hydroboost Braking System
« Reply #8 on: December 04, 2014, 06:48 PM »
today I was loosing power steering fluid for quite a time until I heard the power steering pump.  (there I first recognized it)

Couldn't find where it was coming from and just filled it with ATF Dexron, until it was full again. Then we drove home the last 100 miles. I did check in between and the leaking stopped and the reservoir is still full.
The brakes worked fine, even a little bit better then before.

Which part of the Hydroboost and power steering system is the most likely to develop leaks ? I have to start somewhere.

Offline Rickf1985

  • *
  • Posts: 5595
  • Member since: 2013
  • I own: a Motor Home
  • Year: 1989
  • Make: Winnebago
  • Model: Chieftain
  • Chassis: Chevy
  • Engine: 454
Re: Hydroboost Braking System
« Reply #9 on: December 04, 2014, 07:57 PM »
Usually it will be a pressure hose from the pump to the booster or steering box. If not there check the pitman shaft on the box, That is the one coming out the bottom with the arm on it for the tie rods, the lower seal goes a lot of the times on the Saginaw boxes. Other than that maybe it overheated and blew out the top of the steering pump at the fill cap. Have to look for a concentration of fluid somewhere.

Offline Elandan2

  • 16 Year Member
  • *
  • Posts: 438
  • Member since: 2001
  • I own: a Motor Home
  • Year: 1977
  • Make: Winnebago
  • Model: Elandan II D27DRK
  • Chassis: Dodge M500
  • Engine: 440
Re: Hydroboost Braking System
« Reply #10 on: December 05, 2014, 07:51 AM »
Ours developed a leak in the return line from the hydrobooster to the steering pump.  It would only leak when you pressed the brake pedal and even then it was a really fine spray coming out of the hose.  The only way I noticed it was the fine spots of oil down the side of the motorhome which then got me looking for the source.  Rick 
Treatzall Waste tank sanitizer, lighting, and other RV related products!
Rick Ellerbeck, 1977 Elandan II

Offline eXodus

  • *
  • Posts: 366
  • Member since: 2014
  • I own: a Motor Home
  • Year: 1994
  • Make: Itasca
  • Model: Sunrise 29RQ
  • Chassis: Chevy P30
  • Engine: 454
Re: Hydroboost Braking System
« Reply #11 on: December 05, 2014, 09:19 AM »
thanks Rick and Rick,


seems like you are right guys, just went to investigate and indeed the metal line between power steering and hydro-boost unit is very wet.
Both ends are dry, can it really be that the metal has a hole right in the middle ?


there are two lines mounted to each other, no idea which is leaking. But have probably to replace both just to get one out.

Offline Elandan2

  • 16 Year Member
  • *
  • Posts: 438
  • Member since: 2001
  • I own: a Motor Home
  • Year: 1977
  • Make: Winnebago
  • Model: Elandan II D27DRK
  • Chassis: Dodge M500
  • Engine: 440
Re: Hydroboost Braking System
« Reply #12 on: December 05, 2014, 04:14 PM »
When I replaced ours, I had new hoses made and replaced the steel lines as well.  I couldn't replicate the factory bends in the steel lines with the tubing tools I had, so I re-routed them to allow for easier bending.  That was about 15 years ago and I haven't had to touch them since.  Rick
Treatzall Waste tank sanitizer, lighting, and other RV related products!
Rick Ellerbeck, 1977 Elandan II

Offline DaveVA78Chieftain

  • 14 year member
  • *
  • Posts: 3555
  • Member since: 2003
  • I own: a Motor Home
  • Year: 1978
  • Make: Winnebago
  • Model: Chieftain
  • Chassis: Dodge M400
  • Engine: 440-3
Re: Hydroboost Braking System
« Reply #13 on: December 05, 2014, 09:44 PM »

Quote
there are two lines mounted to each other, no idea which is leaking

Vibration rubbing against each other wore a hole through.

Dave

Offline eXodus

  • *
  • Posts: 366
  • Member since: 2014
  • I own: a Motor Home
  • Year: 1994
  • Make: Itasca
  • Model: Sunrise 29RQ
  • Chassis: Chevy P30
  • Engine: 454
Re: Hydroboost Braking System
« Reply #14 on: December 06, 2014, 06:04 AM »
thats a good point Dave ! thanks

So i will replace both lines. Because the second one will probably start leaking soon after I had bloody hands from changing the first one.


man there a quarter million different hydraulic lines available online. No idea, all look if the could fit but all got different dimensions lol... Is the normal Chevy dealer a good source for these parts ? Or should I get this thing to one of the RV places around ?

Offline DaveVA78Chieftain

  • 14 year member
  • *
  • Posts: 3555
  • Member since: 2003
  • I own: a Motor Home
  • Year: 1978
  • Make: Winnebago
  • Model: Chieftain
  • Chassis: Dodge M400
  • Engine: 440-3
Re: Hydroboost Braking System
« Reply #15 on: December 06, 2014, 10:06 PM »
Would be an auto supply item not a RV place item.  You can try a chevy dealer but most likely to old for them to carry anymore.

Offline Elandan2

  • 16 Year Member
  • *
  • Posts: 438
  • Member since: 2001
  • I own: a Motor Home
  • Year: 1977
  • Make: Winnebago
  • Model: Elandan II D27DRK
  • Chassis: Dodge M500
  • Engine: 440
Re: Hydroboost Braking System
« Reply #16 on: December 07, 2014, 07:51 AM »
Best bet would be to take the old ones to a hydraulics shop that can make up new ones for you.  Probably no more expensive than trying to fine the factory parts.  Rick
Treatzall Waste tank sanitizer, lighting, and other RV related products!
Rick Ellerbeck, 1977 Elandan II

Offline eXodus

  • *
  • Posts: 366
  • Member since: 2014
  • I own: a Motor Home
  • Year: 1994
  • Make: Itasca
  • Model: Sunrise 29RQ
  • Chassis: Chevy P30
  • Engine: 454
Re: Hydroboost Braking System
« Reply #17 on: December 07, 2014, 12:48 PM »
i was just thinking about cutting the metal line right where the leak is and stick the whole metal line into a hydraulic hose and secure it with a couple of hose clamps.

just making the hose nice and warm, use some hydraulic fluid and it should go right over the leaking section. 2-3 inches of hose to the leak on each side should be enough to get it leak free.

this should also prevent future rubbing from the other line which is running near by

but no idea if this idea works with this limited space. because if i have to remove it, it would rather get a new part.

Offline TripleJ

  • *
  • Posts: 256
  • I own: a Motor Home
  • Year: 1985
  • Make: Holiday Rambler
  • Model: Presidential 28
  • Chassis: Chevy
  • Engine: 454
Re: Hydroboost Braking System
« Reply #18 on: December 07, 2014, 05:15 PM »
I replaced the pump and all the lines on my 1985 chevy chassis this past summer.  Everything except a solid hard line between the brake booster and steering gear because it was perfectly solid looking.  Everything was easy to get at Oreillys, and nothing was outrageously priced. :)ThmbUp
'85 Holiday Rambler Presidential '28

Offline eXodus

  • *
  • Posts: 366
  • Member since: 2014
  • I own: a Motor Home
  • Year: 1994
  • Make: Itasca
  • Model: Sunrise 29RQ
  • Chassis: Chevy P30
  • Engine: 454
Re: Hydroboost Braking System
« Reply #19 on: December 09, 2014, 12:38 PM »
since I have to get moving at the weekend and no shop around me has the steering lines in stock
I decided to give the MH to NAPA (just over the street from my place) and let them built the steering lines.

The diagnosed that both lines are leaking: steering-pump to steering gear and steering gear to hydroboost.

Get it back today and they estimated about $250. Not to bad. If I had to do it by myself I had to buy some tools to get the nuts open and the steering-lines which are about 50-80.

Offline tiinytina

  • 12 year member
  • *
  • Posts: 760
  • Member since: 2005
  • I own: a Motor Home
  • Year: 1987
  • Make: Tiffin
  • Model: Allegro 28
  • Chassis: Chevy P30
  • Engine: 454
Re: Hydroboost Braking System
« Reply #20 on: December 09, 2014, 07:09 PM »
not unreasonable.. hopefully near or lower than they estimated...
Hi from Gone to the Dawgs! 1987 Tiffin Allegro in Deale MD. CW Rocks!!!

Offline eXodus

  • *
  • Posts: 366
  • Member since: 2014
  • I own: a Motor Home
  • Year: 1994
  • Make: Itasca
  • Model: Sunrise 29RQ
  • Chassis: Chevy P30
  • Engine: 454
Re: Hydroboost Braking System
« Reply #21 on: December 10, 2014, 03:08 PM »
So I got it back. $218 in Labor and $45 in parts.

First leak:
The metal clamp which was holding both lines to the chassis caused the leak ! It rubbed through one of the metal lines. Just because it was rusty. - I think I will check the rest of the coach for such constructions..

What they did to repair it:
they cut through the metal line - like I was thinking, and installed at both sides couplings on the metal line, then they just added an adapter in between to get the required length.
Since this is a high pressure line this is probably the safest solution.


Second leak:
the line which is going to the hydroboost had have a rusted hose clamp.

Offline Rickf1985

  • *
  • Posts: 5595
  • Member since: 2013
  • I own: a Motor Home
  • Year: 1989
  • Make: Winnebago
  • Model: Chieftain
  • Chassis: Chevy
  • Engine: 454
Re: Hydroboost Braking System
« Reply #22 on: December 11, 2014, 07:06 AM »
I hope they did not use compression fittings on a pressure line. I have seen that done far too many times, they are not designed for hydraulic pressure and could come apart. I have seen them come apart. If it is a return line it is alright but you say it was only leaking once in a while which make me think it is a pressure line.

Offline eXodus

  • *
  • Posts: 366
  • Member since: 2014
  • I own: a Motor Home
  • Year: 1994
  • Make: Itasca
  • Model: Sunrise 29RQ
  • Chassis: Chevy P30
  • Engine: 454
Re: Hydroboost Braking System
« Reply #23 on: December 11, 2014, 07:51 AM »
I'll make a picture, no idea of hydraulics.  In the same line is a rubber hose with a screw hose clamp over the metal-line ? There can not be that hard of a pressure or ?  It is not a brake-line.


I hope it is alright, but since I know how know the part number of this line, I can go online and look for a spare and carry it with me.
They told me what to remove to get there.

Offline Cowinthfog

  • *
  • Posts: 6
  • I own: a Motor Home
  • Year: 1991
  • Make: Fleetwood
  • Model: Bounder
  • Chassis: Chevrolet P30
  • Engine: 454
Re: Hydroboost Braking System
« Reply #24 on: June 25, 2015, 01:21 PM »
Hello, I recently bought my first rv, a 1991 Fleetwood Bounder, 31K on a chevy chassis. I have done quite a bit of looking but have not found a solution to my braking issue here on the site. I have the JF9 4wheel disc system, hydroboosted of course. I had to replace the RF caliper because of severe binding specific to that one wheel. I replaced the front pair. I did not want to pay the core charge, so I took both off and in to the store to buy the new ones. I did not get back to it for a few days.....yes, a mistake to leave the line open so long. With all put back together, I checked the MC reservoir for fluid level only to find the forward half empty. I have not found anything that addresses this amount of air in the line. I have read the entire HB section in the manuals available, an done the system bleed twice with no apparent change. I did try topping off the empty chamber first. How should I proceed? I would not be surprised by air most of the way to the calipers from the MC. Once the system is bled per the book, are the calipers bled normally like old school brakes? Thanks for any help. If there is a thread already addressing this, I could not find it but would be happy to read through it if you could point me to it.


Josh

 

FULL Membership!

Want to start enjoyingall the benefitsFull Membership has to offer?

Become a Full

Want to enjoy your

Full Membership

without ever having

to renew?

Become a:

* Salvage Yards

Find
RV Salvage Yards



By STATE

* Resources

Need parts and information?
View the Resource List
.