More Problems with Brakes

[Dutch Rutter]

Took the advice I was given on another brake thread I made.
I replaced my brake booster (local alignment shop said it was causing my brakes to drag) and my master cylinder (was a leaking POS)
I got a NEW MC and booster from NAPA, installed them, bleed everything.
Pulled the truck out of the garage to find a stupid mooshy pedal with hardly and braking, a woosh sound when applying the brakes (maybe normal?), AND brake lights that now will not turn off (I pulled the fuse for tonight).

My question........ WTF happened? did I get given incorrect parts? and if so which one is the culprit here?
I plan on pulling everything back off the truck tomorrow and matching things up but holy shi+ is doing that a huge PITA.

 

[Rusty Nail]

Did you bench bleed the new master?
The brake lights are controlled by the switch on the pedal - may be unrelated?

 

[Dutch Rutter]

Did you bench bleed the new master?
The beake lights are controlled by the switch on the pedal - may be unrelated?

Thanks for the reply rusty. I did as best I could without a vise. The master came with two plugs instead of the fittings and tubes so I'm not too confident on how well I got it.

The switch hasent been messed with but it seems as though the new setup doesent allow for enough up travel to turn off the brake lights.

So far this morning I pulled the master off the booster and found this small difference, old being on the right and new on the left. Think that would cause these problems?

 

[Itali83]

I literally just replaced my master cylinder last night with one from Napa. Took probably 10 minutes to bench bleed. You need to screw the plastic plugs in that come with master. And pump it by hand until there are no more bubbles in the reservoir. I left the cover off so I could see the bubbles. And once it’s bled fully. You can barely push the plunger in and when you do, oil squirts up out of the reservoir from both sections.

If you’ve never bench bled a master before and your not confident in your bleeding of them. I guarantee you didn’t bleed it enough.

Now, your brake light is on because the proportioning valve shifted from the brakes not being bled enough. That’s why your brake light is on. Forget the parking brake switch, unless you accidentally pushed the pedal. You need to bleed your brakes completely, get a hard pedal and then the brake light will go out. Have fun

Ben

 

[Snoots]

You possibly may have to reset the proportioning valve.

 

[Dutch Rutter]

A little more information on this. I took the booster and MC back off today.

I think I have the wrong booster. Napa will have another new (different part number) booster for me Tuesday. I have bench bleed a MC before and it's worked fine. However. That was using the tube setup, these plugs seemed to allow air to be sucked past them when releasing the plunger.

I am sure that I have air in the lines now and I'll be picking up a reverse bleeder setup to do this chore.

Napa did ask if I had 13 or 11 inch brakes I'm assuming you go off the drum size for that? Which are 13" ID the rotors I believe are 11" or so. The truck is a 3/4 ton camper special with a GVWR of 8600. Would the 13" be the correct answer to that?

@Snoots I'm betting your right about resetting the PC since I've never done that with this truck and this is now my 3rd MC/booster setup to put in it. How does one do that?

Thanks all for the help. TBH these issues with the pickup have had me at my witts end and really wishing I could justify spending the $30k+ on a used 2014 with 70k miles. But thats an entire other story.

 

[Snoots]

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How to Reset a Brake Proportioning Valve

A brake proportioning valve is typically located in the rear brake line and enables you to adjust the rate of pressure increase to the rear brakes. It changes the proportion of brake fluid. You can slow down the pressure increase that happens when you apply the brakes with a brake proportioning...

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