break problem!

O

outlaw62

New member
I have a 1974 150 camper special all origional,disc in front drum in rear, problem is when in drive I have 100% breaks,put it in reverse pedal is hard and will drop to floor with 100% total loss of breaks,it did it once in drive as I was pulling into a parking space,pedal to floor,crunch and quickly realized no bmw is a match for a 74 IH bumper never had this happen any ideas?
 
What's the fluid level like in your m/c reservoir? When was the last time you inspected the wheel cylinders? If the reservoir is low, you have a fluid leak somewhere. Try disconnecting and plugging the vacuum line to the brake booster to see if that changes anything. Bottom line, this is either a fluid issue or a vacuum issue. If the engine is running well, I'd be more suspicious of a fluid problem.
 
The fluid level is at 3/4rear full in front,when I step on the breaks you can hear air being pushed from under the dash,kinda like airbreaks on a truck,bad booster? All cylinders are dry,should I bleed them or is there another thing I could try,
 
If the pedal goes to the floor, ever, and the cylinders are dry, then the most likely problem is the master cylinder is leaking. I would start by replacing the mc with a new, not rebuilt, one.
 
You shouldn't be hearing air escaping when the pedal is applied. You don't have air brakes. If the fluid level is staying put over a period of days and weeks and you aren't having to top it off, then you don't have a fluid leak. If you're having to top it off, even once a week, you have a fluid leak somewhere, and possibly from the mc into the booster. If it were me, I'd be homing in on the whooshing sound when you hit the pedal. That for sure isn't right.
 
From the original description the pedal drops to the floor. If fluid is not coming out of the system, then it is bypassing the internal seals in the mc. That is probably why the front reservoir is full and the other low.

There May be a second problem with the vacuum booster or there May not, but the pedal going to the floor can get someone killed and should be addressed first.

The other symptom described is that brakes work going forward, but not reverse. Drum brakes will exhibit that behavior, disks won't. My guess is that the back circuit, which is for the front disks is bad and the the truck is primarily stopping with the rear drum brakes. The difference in the levels in the reservoirs confirms this.
 
Is there a way to confirm the booster is bad or do I just assume it is and just replace it,I did take a metal rod and addlied pressure to the pedal and left it there all night and this morning it was still in the same position,so im assuming there isnt a leak,but did take it out and at 20 mph stood on the breaks,they went half way down got hard but didnt slow down,let up and applied them slowly and they worked like normal,im starting to wonder if it all needs to be replaced
 
My swag from your description is it is just the mc, but if it the booster they usually come with a mc. It depends how tight funds are, the external condition of your current booster (is the housing badly rusted, rotted grommet for vac connection).
 
Them boosters don't be lasting forever. And after 39 years of service it's getten fairly whooped. My gut fealing says replace bothe the booster and the master cylinder
 
You must log in or register to reply here.
Back
Top