Community Forums

Krazzykitt · 06-19-2011, 03:42 PM

Its weird the auto brake light would come on sometimes when driving and sometimes when parked, when I first bought the mh I thought the auto brake was on when driving it home cause I smelled brakes for a couple of minutes, but it went away, no light came on but when I got it home I noticed the brake light on, maybe it was on all along and just didnt notice it.
So now im going to pull the whole unit, master and hydro, but I really dont think its the master cylinder, something tells me that ill put a new one on and it will do the same thing...pedal goes to floor, the pedel never gets hard even with the engine off.
And im wondering...is the hydro unit supposed to come on even if the key is off? Cause I can put my foot on the brake and hear the electric motor kick on.

She and I · 06-19-2011, 04:03 PM

Quote:

Originally Posted by Krazzykitt

Its weird the auto brake light would come on sometimes when driving and sometimes when parked, when I first bought the mh I thought the auto brake was on when driving it home cause I smelled brakes for a couple of minutes, but it went away, no light came on but when I got it home I noticed the brake light on, maybe it was on all along and just didnt notice it.
So now im going to pull the whole unit, master and hydro, but I really dont think its the master cylinder, something tells me that ill put a new one on and it will do the same thing...pedal goes to floor, the pedel never gets hard even with the engine off.
And im wondering...is the hydro unit supposed to come on even if the key is off? Cause I can put my foot on the brake and hear the electric motor kick on.

Krazzykitt, Ok lets not start changing parts ...think for a minute...even if you had no hydraulic assist you still should have brakes...not good brakes but a brake pedal feel.the electric motor you hear running is the backup for the hydraulic or hydro assist ,if the engine dies.....If the engine dies you have no power steering .....which feeds the hydro assist with oil to work...the electric motor is supposed to keep fluid flowing.. so you can stop the rv...
Do you have power steering and does it work properly? Is the reservoir full?..cause this is where your brake booster gets the fluid to work..
Richard

Krazzykitt · 06-19-2011, 04:30 PM

See heres the thing, the power steering works just fine, under the hood theres a power steering reservior, normal size, and next to that is the hydro boost reservior that holds about half gallon of dextron 3, so theres 2 seperate systems, the hydro boost seems to be a stand alone system, is this right?

jeepfreak · 06-19-2011, 04:48 PM

The hydroboost gets it pressure from the power steering pump. You should see lines going from and to the pump..That is unless john deere used only an eletric pump. When you open the bleeders does the pedal go to the floor? When there closed does the pedal get real hard?

She and I · 06-19-2011, 04:53 PM

Quote:

Originally Posted by Krazzykitt

See heres the thing, the power steering works just fine, under the hood theres a power steering reservior, normal size, and next to that is the hydro boost reservior that holds about half gallon of dextron 3, so theres 2 seperate systems, the hydro boost seems to be a stand alone system, is this right?

Krazzykitt,...........Ok,The brake booster has to have a pump... where does the lines from the reservior go to? the power steering pump ? or does it have its own pump?.....Just so you know I have no manuals for your RV so we are ....as we say! Flying by the seat of our pants.

Krazzykitt · 06-19-2011, 05:32 PM

It looks like it has its own pump. A mechanic I know just told me that if the seal in the hydro boost is blown then its not allowing the rod.to push the master cylinder, therefore no pedal. Does this sound right?

She and I · 06-19-2011, 06:08 PM

Quote:

Originally Posted by Krazzykitt

It looks like it has its own pump. A mechanic I know just told me that if the seal in the hydro boost is blown then its not allowing the rod.to push the master cylinder, therefore no pedal. Does this sound right?

Hey Krazzykitt.........But you still should have brakes ...even if the booster or pump quit working.....Back up a little.. you said the brakes worked but you smelled burning brakes..and the brake light was on....that was maybe the parking brake burning as you drove, the park brake is hydraulic released and spring applied........Try this fill the hydraulic tank and open the bleeder on the emergency brake.. and try to bleed the hydraulic system.. see if you have air in the system.........(But I think you still have air in the brake fluid side of the system)...you should have brake pedal... maybe hard to press the pedal... but a brake pedal.

Not to add more to think about... but there are recalls on the auto brake lines for your JD chassis. You need to yahoo.. JD rv chassis auto brake recall.......
Richard

Krazzykitt · 06-19-2011, 06:20 PM

This all started because the front brakes were dragging, has anyone ever had a problem with the propertional valve going bad? Im throwing a lot out there but my brakes dont work, maybe thats why I got the mh so cheep, lol. So heres what I got, started with front brakes dragging...only after driving for 10 min or so... Went to bleed system, had pressure first few pumps then the seal went out on hydro boost, now no brakes...

Mekanic · 06-19-2011, 06:21 PM

Quote:

Originally Posted by Krazzykitt

......Heres the story, over the last couple of weeks when I would drive it short distances the brakes would start dragging, the peddle would get hard and it would get to the point where id have to stop, when the brakes are cold they work fine........

I have seen this part before. there are 2 possiblitys.

1 has anyone done any exh work lately?? I have seen cars where a new pipes have heated the brake fluid to the point of pressureizing it and that applys the brakes slightly make the problem worse.

2 with the age of the vehicle one or more of the flexable brake hoses may have gone soft inside. this can sometimes lead a hose acting like a check valve and holding pressure on a caliper.
This can also lead to makeing it hard to get anything out of the lines.

RVhauler · 06-19-2011, 11:12 PM

If wrong fluid was used then i question the effect of it on the seals/rubber parts of the system. Suspect there could already be damage exsisting

Krazzykitt · 06-20-2011, 12:36 AM

I just read about electric assist brakes, someone was having problems with their mh brakes and apparently john deere used the electric assist in the late 80s, so now im more confused. So I have electric assist brakes? there is an electric unit by the master cylinder, even if the key is off and u press the brake u can hear the electric motor kick on. Ive never heard of electric assist, can someone confirm this?