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Topic: Brake hydroboost on my 1990 grandvilla , Oshkosh v815 chassis  (Read 601 times) previous topic - next topic

Brake hydroboost on my 1990 grandvilla , Oshkosh v815 chassis

Hya all , I was thinking it might be an idea to check if my hydroboost electric back up pump is working or not , IL be honest I don't  know if it has ever worked , it's only since I've been reading through all the manuals and fitted a new master cylinder that I realised that one does exist , I cannot hear a sound , when engine is off and the ignition is on, so I'm thinking perhaps it wouldn't be a bad idea to check it out , I would hate to think if ever I had a power steering pump pack up on me that I didn't have some kind of back up braking system , so this job now before anything else takes priority ,  I'm thinking , I haven't driven it anywhere for 8 years , before that the electric pump may have not ever come on , it's a piece of electric equipment that never gets used , except when  you have a power steering pump go on you , are these pumps designed that well that they never fail because there not used mutch , or do they fail because of lack of use , what would be my first step to checking the pump , I presume just two wires coming from pump , 1 positive 1negative , so a direct live source connected to pump should tell if pump is ok or not , would anyone agree or disagree with what I need to do  , from what I've read there is a flowswitch , so if transmission fluid suddenly stops pumping for some reason , this flow switch should turn on electric pump , I'm not sure best way to test out flow switch though , and also if my power steering pump was to pack up and the electric pump was working , does it just keep my brake hydroboost working , or will it aid the power steering aswell?
1990 foretravel grandvilla, Oshkosh chassis
8.2ltr Detroit turbo

Re: Brake hydroboost on my 1990 grandvilla , Oshkosh v815 chassis

Reply #1 –
Don't have that system on our GV, so I can't help with this question.  Sorry.
1993 U280 SE 40' WTBI, Build: 4359
C8.3 300hp, 6-Speed, Exhaust Brake
960 watts on the roof (6 x 160)
Sorento (or BOLT) on a Kar Kaddy SS
"Nature abhors a vacuum"

Re: Brake hydroboost on my 1990 grandvilla , Oshkosh v815 chassis run

Reply #2 –
It is just for the brake not sure as it has been a long time since I worked on that system but think if the key is turned on and engine not running if you step on the brake the pump should run. Nitehawk can probably better answer this.
previous 1984 35 ft ORED 250 HP 3208 Cat       
previous 1998 40 ft U295 CAI 325 hp Cummins
previous 2003 40 Ft u320 build #6140 450 Cummins M11.                                                         
1999 Mazda Miata
Ron, Nancy, Tipper the cat, Max The dog
1997 U 270 36 ft build number 5174 8.3 Cummins

Re: Brake hydroboost on my 1990 grandvilla , Oshkosh v815 chassis

Reply #3 –
Quote from: red tractor –
It is just for the brake not sure as it has been a long time since I worked on that system but think if the key is turned on and engine not running if you step on the brake the pump should run. Nitehawk can probably better answer this.

Correct.

But. with the electrical issues you are having with the ignition circuit, it may be fine and just not getting the "ignition on" signal.
Brett Wolfe
EX: 1993 U240
Moderator, ForeForum 2001-
Moderator Diesel RV Club 2002-
Moderator, FMCA Forum 2009-2020
Chairman FMCA Technical Advisory Committee 2011-2020

Re: Brake hydroboost on my 1990 grandvilla , Oshkosh v815 chassis

Reply #4 –
Are you sure you don't have the "electric assist" motor mounted right next to the bottom of the brake pedal under the floor?
Our coach has that assist and I had a near catastrophic accident in Laredo when the assist didn't function. Turns out the bayonet connectors were so loose that electric current didn't flow. Tightened the female bayonets and no problems since that time--about seven years ago.
Nitehawk,  Demolition Lady, & our NEW master, Zippy the speeding BB cat.
1989 Grand Villa 36' ORED
Oshkosh chassis, 8.2 DD V8
2006 Saturn Vue AWD

Re: Brake hydroboost on my 1990 grandvilla , Oshkosh v815 chassis

Reply #5 –
Our 2004 Holiday Rambler had a hydro boost. If I recall you could hear the hydro boost cycle when you shifted from park too drive. Your foot had to be on the break.
Alan Fink
Waupun, WI
2000 Blue Bird Wanderlodge  LX40
2018 F150 4x4
2020 Jeep Wrangler Unlimited  Rubicon JL

Re: Brake hydroboost on my 1990 grandvilla , Oshkosh v815 chassis

Reply #6 –
My '88 Winnie on a '87 John Deere chassis had one too. Foot on the brake, key on, engine not running, you could hear the electric motor running.

This was a front engine gasser.
Tom Lang K6PG (originally  KC6UEC)
and Diane Lang
2003 38 U295 build 6209
2016 Jeep Grand Cherokee Summit Ecodiesel
still have tow-ready 2006 Acura MDX 
Temple City, California
Motorcade 16681 California Chapter President
SKP 16663 member of SKP Park of the Sierra, Coarsegold California
FMCA F071251
Retired electrical and electronic engineer

Re: Brake hydroboost on my 1990 grandvilla , Oshkosh v815 chassis

Reply #7 –
Quote from: nitehawk –
Are you sure you don't have the "electric assist" motor mounted right next to the bottom of the brake pedal under the floor?
Our coach has that assist and I had a near catastrophic accident in Laredo when the assist didn't function. Turns out the bayonet connectors were so loose that electric current didn't flow. Tightened the female bayonets and no problems since that time--about seven years ago.
I'm not sure IL have to have a look, , looking at the workshop manual there is a seperate pump attached to the brake booster, I'm just waiting for the rain to stop and dry ground , that's what holds me up most of the time, I dont mind cold weather , bit hate lying down on wet ground , soon as I get the chance IL check that out thanks norm
1990 foretravel grandvilla, Oshkosh chassis
8.2ltr Detroit turbo

Re: Brake hydroboost on my 1990 grandvilla , Oshkosh v815 chassis

Reply #8 –
Hya norm , just got in got my manual , hopefully the attachments are all back working now , Ive took the photos of power head and electric standby pump , if I'm right do you have a slightly different chassis to mine , if I recall you have a v817 chassis where as mine is v815 , could explain why yours is under floor near brake pedal
1990 foretravel grandvilla, Oshkosh chassis
8.2ltr Detroit turbo

Re: Brake hydroboost on my 1990 grandvilla , Oshkosh v815 chassis

Reply #9 –
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1990 foretravel grandvilla, Oshkosh chassis
8.2ltr Detroit turbo

Re: Brake hydroboost on my 1990 grandvilla , Oshkosh v815 chassis

Reply #10 –
Norm , there is a brake pedal switch for this elecro pump , but reading this article the pump is attached to the power head ,  as soon as it's dry weather , first thing I'm going to test is the pump itself , if it works then IL go to the switch, and check there is power in and out , process of elimination it will have to be, once I have it sorted and everything checks out , it wouldn't be  a bad idea to wire a seperate live feed with a dash switch, so if ever I had a problem with pump not switching on, with pedal switch then I can turn it on direct if ever the power steering pump failed, also once a week I could run the pump for 5 or 10 mins, just to keep it in good working order
1990 foretravel grandvilla, Oshkosh chassis
8.2ltr Detroit turbo
 

Re: Brake hydroboost on my 1990 grandvilla , Oshkosh v815 chassis

Reply #11 –
I am amazed, thought all Foretravels had/have air brakes, not that oily stuff.
1988  40' Grand Villa Cat 3208t