texasrvr
Texas
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I have a Allegro Bay MO on a Chevy P30 chassis with the Chevy 454 engine. This unit uses a single pump called a powerbooster that furnishes hydraulic power to the brakes and power steering.
The original unit had problems (wear & tear) and I had it replaced.I did it right after I had purchased the unit so I was not to familiar with it's normal characteristic's as far as noises it produced while driving. The old unit howled like a banshee and locked the right front brake caliper when attempting to make a right turn and other goofy stuff. With that happening I could not judge the new ones normal operating noises.
Well the new unit operates ok and has not given me any problems but it whines after the unit gets warmed up. I know that some hydraulic pumps whine as I have a tractor with a hydrostatic transmission and it whines and makes different noises when I speed up or go into reverse.
Being as this unit is front engine gasser it is noisy and the whineing is clearly audible and changes tone as I turn or use the brakes.
The question is - is this whineing a normal thing with GM powerbooster pumps on the P30 units?
Thanks.....
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Geozzz
South Jersey
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The unit might whine when started in cold weather but as soon as it is warmed up it should not.
Kathy & George Zimm
Mickleton NJ
2006 Coachman Epic and 1 Sheltie
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lirv
Northport,NY
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No. I have hade 8 trucks with it and none have whined. It is called a hydroboost unit. Only replacements that are any good are AC/Delco reman. ones from the dealer.
2006GMC,3500SLT,LBZ,225x19.5,2004 Carriage CW362,Mor/Ryde Pin Box,Pullrite Super Fifth,Brakesmart
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jenks60
MS. coast
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Joined: 10/27/2001
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Is it the power steering pump that is howling? Mine howled like crazy right after I bought it and I found the vent (on top of cap) hose was pinched causing a vacuum on the pump. If the reservoir is not at proper fill it may make it howl.
There is a way to bleed the hydroboost, but I don't know how.
HYDROBOOST
What year is your RV?
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jenks, fulltiming with the DW.
92 Southwind P3(32) 33 ft.
99 Saturn SL2
Rallys attended-TX 2, LA 2, MS 1, AL 2
MA. 1 drop in for visit.
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texasrvr
Texas
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Jenks 60
I have a 93 Allegro Bay 34' and I tow a 02 VW Turbo Beetle. As far as the oil level and the tube. When I had it replaced it was overfilled at the Chevy dealer no less. Somewhere west of Amarillo it dumped some oil due to heat expansion I guess. This kind of made a mess on my toad because we were passing thru some light rain and there was some crud on the road. I since have rigged a canister to catch any thing else but it shows that it is in operating range on the dipstick when hot. As far as working it seems to be fine and it whines more when it applies pressure such as turning the wheel at a sharp angle (not to the stop)like getting into a gas station or applying the brakes. Going down the road it has a low steady tone but it's not giving me any trouble. (yet) So far I have put 3k miles on it on our last trip to CA and that was my only real problem other then having a total engine shutdown at 60mph. Got it restarted and it has not failed again. Showed no codes on the computer so it is a mystery. Of course it was white knuckle time as when that happens the powerboost is gone so no PS or PB.....
THis was a RV that was sadly neglected and I was able to get it reliable for about $7k plus original cost so I have less then $20k in it. The best part it is paid for and it is comfortable for the two of us. The original owners were pretty clean folks but did not take care of the running gear and so it needed some major work.
Tip - If you are running a GM type shop around for running gear repairs. The local RV shops charge from $115 to $135 per hr but the local Chevy dealer charged me $85 per hour and warenteed the parts and work... etc... (Dallas area)
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sum1
So-Cal
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What chassis year? Is this the belt driven pump?
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texasrvr
Texas
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sum1
It's a 1993 Allegro but I'm pretty sure the chassis was built in 92. It is a Chevy
P30 with a 454 engine. The pump is belt driven as far as I can see under the doghouse. It was replaced last Sept with a GM rebuilt unit at the local Chevy dealership.
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jenks60
MS. coast
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I am thinking air in the auto park brake actuator. I went through that with mine. There is a bleeder valve (like on brake cylinders) on rear top of actuator. I would try bleeding it. I think you would need to have engine running,(level, with wheels chocked) put in drive then put in neutral, shut off engine, crawl under there and loosen the bleeder valve, as soon as fluid comes out, close valve. That is all I can see that would make the fluid overflow and then have the pump howl.
OH, I forgot to ask, is the actuator leaking?
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sum1
So-Cal
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I'm guessing then, that your PS pump serves the PS, Hydroboost Brake Booster, and the AutoPark. Your Reservoir may be just to the port side of the radiator.
As Jenks said, bleed the AutoPark Actuator after chocking the wheels on flat ground, etc. It's located on the right frame rail, aft of the transmission. Understand that the AutoPark Actuator is in its relaxed default state is when it's in Park. A powerful spring applies the driveshaft mounted Brake. Fluid pressure is required to disengage the Brake.
Air is compressible so it can cause more fluid to flow than is normally required. Don't let the Reservoir go dry! Check its level in Park cause it drops several inches when out of Park. It will gush out if you fill it when out of Park then put in Park.
After bleeding the actuator, put it into Park and top off the fluid level. Raise the fronts if possible to reduce strain, start the engine, and slowly turn the steering wheel from stop to stop a half dozen times or so to bleed the PS system. No need to bump the stops hard. This should clear out most of the air from the PS, HydroBoost Brake,and AutoPark systems. Recheck the fluid level. If the fluid is foamy, repeat tomorrow.
A coupleof points here:
-The AutoPark replaces (in most cases) the Park Pawl in the tranny.
-HydroBoost is a hydraulic service brake booster that replaces the vacuum booster found on many cars.
-The Master Cylinder itself gets Brake Fluid which is separate from the PS fluid boost circuit. Don't mix them up.
Let us know how this works out.
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texasrvr
Texas
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So-Cal
Thanks for the info. Sounds like you have been through the drill more then once.
The reservoir is exactly where you said it is located. I don't think I have a autopark system on my rig. There is a large brake drum on the driveshaft but I think it is part of the parking brake actuated by the parking brake pedal. I have only been under it a couple of times but only looking for any leakage and to check the installation of new air lifts in the front springs.
The oil level right now is right in the middle of the operating range markers on the dipstick when hot so I'm pretty sure I have the proper levels. This installation was done at a Chevy dealer who has a large truck and rv section and the whole thing, brakes, ps, pb, radiator, fan clutch, and water pump was done under the supervision of the service manager due to a earlier screw up of brake repairs and it was test driven by him for over 50 miles. He also is a RV owner and knows what is going on.
I will check out if in fact it has a autopark feature installed and look for the actuator where you describe it....
Thanks....
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