Rock hard brakes

[Giles]

Hi there chaps

Just purchased my first Rv a 1977 Chieftain and to be honest i should of walked away, seems to be a theme with most things i buy. Anyway i have it now and what is my biggest concern is the lack of brakes, i have read lots of post but could not find the same problems. These are my main issues.

Rock hard pedal, virtually no brakes, brake pedal shakes violently when driving.

Any ideas would be much appreciated

Giles

[Oz]

Hang in there, Giles.  Many of us had the feeling we "we bit off more than we could chew" once we'd gotten our vintage RVs, me included.  But the good news is, you have a whole gang of experienced people here to help!  Believe me, you'll get all the guidance and moral support you need to get that Chieftain up and running right.

If you don't have one yet, be sure to get the manual for it right off.  The eManual is available in the club store.  You can print the pages you need to use while getting into the nitty-gritty of things whenever you need to.

[Giles]

thanks good to know, she is a good looking beast but is in terrible condition, if the brakes worked then atleast it would be drivable and i guess then i would get some sort of enjoment out of her and we would become bestfriends. I would not be happy to sell it with the brakes as they are so even if i was to pass the batton to a better man I would first have to win the brake war.

[Elandan2]

Hello Giles,  The hard pedal could be the result of a seized piston on the front brakes.  The shaking may be caused by a warped rotor.  That would be the best place to start, at the front brakes.  All the parts are fairly easy to come by, although they may be pricey.  Let us know how you make out, we've all been there, brakes on a Dodge chassis is always a source of frustration, but can always be repaired.  Rick

[Giles]

the guy i purchased it from said it had been stood for 3 months and the brakes would need a few miles to bed in. after 150 miles of terror the brakes were exactly the same.

[doylexl]

Normally the brake pedal is hard and doesn't stop well because the power brakes are not working.

The brake master cylinder should be mounted to a large black round thing called a brake booster and it should be getting vacuum from the engine at the intake manifold . You should look at the brake booster and make sure the vavuum hose is connected and make sure it has a suction on it when tbe engine is running. You can disconnect the hose from the brake booster with the engine running and hear a sucking air noise. If you don't have good vacuum at the booster then trace the hose to the engine and make sure it is connected. If you have good vacuum at the booster then the brake booster could be bad. It has a diaphram inside and it could be ruptured.

If the brake pedal is knocking when you apply the brakes then you most likely have a warped front brake rotor or an out of round rear brake drum. Normally te drums can be resurfaced and fix that problem.

[Giles]

Thanks for the advice, i have had lots of old wrecks over the years but i never had one where the brake pedal visually moved sideways about an inch quite quickly when driving. What you say seems logical to me that the lack of brakes could have something to do with the booster as the brakes will work a bit if i stand on the pedal and pull on the steering wheel.

[Elandan2]

A 77 M400 chassis has Hydroboost brakes, that could be causing your hard pedal trouble and lack of braking.  Does the power steering operate okay?  The Hydroboost system uses the power steering pump to build pressure.  Rick

[Giles]

Hi Rick


yes the steering is fine, I think I will get the front brakes stripped down and with a bit of luck there might be something obvious.

[DaveVA78Chieftain]

I suggest you read this general hydroboost information. 
http://www.brakeandfrontend.com/issue/article.aspx?contentid=38431

and procure the 76-77 MH Chassis manual from site store
http://www.classicwinnebagos.com/forum/index.php?action=store;sa=view;id=203

Might save you  lot of pain and agony.

Dave