Stiff Brake Pedal

[blue bronc]

I have searched and am not finding what I am looking for on this topic.
I had the 77 sittng for a few months while I did the EFI swap.
Whil i had it up I put new pads on the front and now the pedal is very hard.
I have limited stoping power and cannot lock the wells up. I never had issues before with the brakes and it was easy to lock them up.
A budy told me to open the valve and press the pedal to possibly reverse the valve in the H block that have moved inthe wrong direction when I compressed the caliper piston. I did that tonight pedal went to the floor and I found no air in the system.

What is the next step?
Please dont say hydroboost. I have a unit sitting in the shop for later I just want to drive right now while the weather is good.

Thanks
Mark

 

[broncnaz]

What pads did you install? Some of the new high dollar fancy cermanic or specailty pads dont stop well at all until they get hot. Firmer pedal is probably just from the new pads so its taking less pedal travel before they start working. Also sometimes it takes new pads a little while to seat in. When they seat in braking becomes better.
my last idea would be that the caliper pistons may be stuck(dirt, corrosion ect) so you get a firm pedal and little braking

 

[DirtDonk]

Two other things I can think of.
One is, did you get the slider clip-and-spring thingy back in correctly? Either way, was it particularly hard to get the slider in on either of the calipers?
The other is, if you bled the brakes during the initial process, did you pull the delay-valve pin on the proportioning valve?

Paul

 

[Annapolis76EB]

I am sure you already checked this, but did you verify you have manifold vacuum to your power booster? Your symptoms sound like an issue I had a while back when my vacuum line came off of the manifold. Likely not your issue, but I always check the easy stuff first.

 

[blue bronc]

The pads are Wagner semimetalic pads. I can understand that they need to seat in but I cant stop even at low speeds with out stepping on it hard.
Paul: Now that I think about it I was only able to get one of the springs back in and that caliper was very tight on reinstallation. I did not pull the delay valve pin did not know to do it.
Annapolis: I have the vac line hooked to the manifold but I will double check to make sure.

So is the best route to go back uninstall everything and press the pedal to ensure calipers are closing. Remove the delay valve pin compress the calipers, reinstall all of it pads, calipers bolts and springs and hope all is good.

 

[Apogee]

I am sure you already checked this, but did you verify you have manifold vacuum to your power booster? Your symptoms sound like an issue I had a while back when my vacuum line came off of the manifold. Likely not your issue, but I always check the easy stuff first.

That was my first thought too...adding EFI, it would be easy to lose track of the vacuum hose for the booster. As for your calipers, they should slide relatively freely, with the only resistance being from the spring clip and friction from the guides. Make sure you've lubed the slides with grease or anti-seize to keep things moving freely in the future too.

 

[ohpoo2]

It does sound like booster went bad or no vac.

 

[Broncobowsher]

If the vacuum booster went bad it you could pull the vacuum line and drive it. If the brakes are just as bad, booster. If they are even worse, you need a different set of pads. No pads with a lifetime warranty.

 

[blue bronc]

Does it matter which vac port the booster it is attached too on the intake?
The pads are Wagner Thermo Quiet they do not have a lifetime warrenty.
So all I need to do is pull the vac hose and see if it is worse. If it is I have a bad booster. If not it is somthign else.
How likely is it that the pistons are just stuck?

 

[broncnaz]

Basically you only need to put your foot on the brake pedal and start the engine if you feel the pedal go down slightly then the power brakes are working. While a bad booster does make the brake pedal a little harder than normal it should still stop well. I'm still voting on a stuck caliper. Its a likely issue as when brake pads wear the piston has moved outward in the bore as time goes by brake fluid collects moisture rust develops in the system many times the bore surfaces once you replace the pads and retract the pistons they may come in contact with rust/dirt in the bore and basically stick hence the hard pedal and low braking power they may even have cocked slightly due to the rust and may be jammed.

 

[Annapolis76EB]

BTW, and again likely unrelated to your issue, I just put the Wagner Thermoquiets on my wife's Camry this Sunday and I am definitely not impressed. You really have to put a ton of pressure on the pedal to get the same stopping power you could get with half the pressure on her semi-metallics. I have run ceramics before without issue, but these definitely don't seem to be up to snuff. On a positive note, they really are quiet.

 

[Broncobowsher]

My instinct says to change the pads...

 

[blue bronc]

I wanted to thank all of you for your responses and information.
As it turns out I am an idiot and with the help of Pedestrian I realized the port that the vac line was attached to was not actually a vac port. It was for water flow through the upper intake.
As soon as I changed it the brakes were all there and I could lock them up with no problem.
Again thanks for all of your help.

Mark

 

[Apogee]

Glad it was something simple...while maybe a little embarrassing, that's better than coughing up a bunch of money for new calipers, pads, booster, etc only to figure out that it was a vacuum connection in the end.

 

[Annapolis76EB]

Good to hear it was an easy fix. I have learned the hard way to check the easy stuff first.