hydroboost diagnosis test

Golden_HVAC wrote:
What model year is the RV?

WHat brand?

Do you have GM or Ford chassis?

Have you changed the brake fluid recently? Or ever?

Is there a front caliper flex line with a bubble on it when the brake pedal is pressed really hard? That can cause really spongy brakes. Normally once the RV is over 20 years old, the front flex lines should be replaced, regardless of how 'great' they look.. .

If it is a class C, is there transmission fluid behind the drivers side carpet on the inside? This would indicate a bad hydroboost, and they can be really expensive. Mine cost $950 from a truck supply place in Long Beach where I used to work, and they gave me the fleet price - back in 1994 or something, so with inflation, they probably run $1,500 or more now. . .


What fluid is dark? power steering or brake fluid? Both can get dark when they are older.

While at it, check out the transmission fluid. If that is dark too, then start saving for a new $3000 transmission. .. Change the transmission fluid as soon as possible if it is dark or smells bad. You will still be leaving about 1 gallon of fluid in the torque converter. Then only way to get all out is flush it, but still some will remain, say 15% or 10%. The only true way to get rid of most all of it is to change it twice in a row. Then 75% or more is replaced the first time, and the additional 3 gallons of fluid will dilute anything that remains. Changing it again within say 1,000 miles will get ride of most of the old stuff, leaving the new stuff to 'dilute' some not so dirty transmission fluid. . .

Fred.

It is a class a gm 92 thor pinnacle.I have never changed the brake fluid but i have recently changed the power steering pump because i was getting a lot of noise from it and that cured that but i have always had a problem with the brakes that seem to take a lot of effort to stop and a lot of travel before getting any feel.I have not really been to worried about it untill the light started coming on which to me indicates a problem.Not sure if it should come on when there is air in the system?I am not sure what a flex line with a bubble on it is or if i have ever seen one but sounds like something i should check for.