Spongey/Air-y feeling at bottom of pedal

[100Timelord]

97 Ford Ranger (72k miles), RWD W/ Rear ABS only

Alright, I just changed out the front rotors, pads, and bearings. Plus some odds and ends that had worn out. Small change, I know, but it's the first brake work (or major fix in general) I've ever done, so it's big fish for me, capeesh?

Anyhow, doing so did fix the steering wheel shaking during braking, improved the stopping power, and (I think?) got rid of a squeak (and 'bearing sound') coming from the front left.

However, it did not fix a spongey feeling and "air sound" from the brake pedal at the end of it's travel. I cracked the master cylinder when I compressed the caliper pistons, and I noticed A LOT of fluid overflowing. Is this normal on a front brake replacement? It was almost as if someone had seen the fluid was low, so filled it instead of servicing the brakes (I bought the truck 2 weeks ago).

What I'm asking is, is this behavior normal, or do I need a brake bleed or something else? I think the rear drums are in poor shape, as the parking brake does not hold the truck stationary when in park, and though I feel them drag, I don't feel much pull from the rear when braking. Of course, maybe this is normal/a different issue so input on the rear drums would also be useful.

Thanks, and Godspeed

 

[sgtsandman]

With drum brake equipped vehicles, rear braking power is normally about 30%. So, there isn’t a lot there. Allowable shoe thickness is pretty thin. So you may or may not be good on those.

For the parking brake. Check your cable movement and make sure they aren’t sticking. They can freeze up from corrosion and built up dirt over time. Changing the offending cable or cables is the only fix.

Also, check your adjusters to make sure they are working properly before you change anything. If they are seized or are stiff, they could be your problem for both braking power and parking brake effectiveness. The adjusters not working properly COULD be contributing to your spongy brakes.

For the spongy brakes, with the described noise associated with the braking, it could be a master cylinder issue. The internal seals fail over time. So that is one possibility. When the hissing noise appears, does your engine rev up? If so, it could be a brake booster issue. If not, you’re back to the master cylinder.

 

[Uncle Gump]

When you push the front caliper pistons back into the caliper... the fluid has to go somewhere. It goes back to the master cylinder. Depending on how full it was... brake fluid spillage is normal.

Brakes should never need to be bled unless you've opened the hydraulic system or it has a leak.

I would bet all your pedal issues are because the rear brakes are out of adjustment. The next thing you should do is to remove the rear drums and give them a good inspection. Repair anything that is questionable and give the rear brakes a proper adjustment. The rear brakes being adjusted loose will give you a low spongey pedal

 

[100Timelord]

For the spongy brakes, with the described noise associated with the braking, it could be a master cylinder issue. The internal seals fail over time. So that is one possibility. When the hissing noise appears, does your engine rev up? If so, it could be a brake booster issue. If not, you’re back to the master cylinder.

The engine does not change idle at all with the pedal depressed. I think the master cylinder may have been serviced recently? The previous owner did not keep service records, but I know at least the brake lines coming out of the master cylinder were recently replaced.

 

[100Timelord]

When you push the front caliper pistons back into the caliper... the fluid has to go somewhere. It goes back to the master cylinder. Depending on how full it was... brake fluid spillage is normal.

Brakes should never need to be bled unless you've opened the hydraulic system or it has a leak.

I would bet all your pedal issues are because the rear brakes are out of adjustment. The next thing you should do is to remove the rear drums and give them a good inspection. Repair anything that is questionable and give the rear brakes a proper adjustment. The rear brakes being adjusted loose will give you a low spongey pedal

Yes, the rear drums were next on the To-Do list anyways. Thanks for the input, and I'll see what a little tinkering can do. I'm sure gonna need a new can of brakleen!