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Stiff brakes


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New member here, first post. I am having an issue with my brakes. Carburetor creating plenty of vacuum, no leaks in the line from the booster to carb. Check valve working properly and the booster does seem to be operating properly and holding vacuum as verified by testing the pedal. Yet it is very hard to stop the car. I really have to press down the pedal hard to get the car to stop. Is it possible that the booster itself is the incorrect booster?  Like maybe it’s working but just under capacity required for the car? Any thoughts or ideas would be welcomed and appreciated, thank you. 

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Tube is clear of obstruction, check valve is working, I tested it separately. I took the compression nut off of the tube and cleaned the Teflon off. Then cleaned the adapter. Started car without the line hooked up and the carb is drawing a massive amount of air. Sounds like a jet! Reassembled without Teflon (because it’s a compression fitting) and so I believe it’s all sealed and connected properly. 
 

Calipers look new, pads and shoes are good. Rotors and drums are good. The brakes do grab and stop the car, it’s just very hard. I picture my great grandma driving this car as she had one in the 70’s. And there’s no way she would be able to stop this car. I can stop it because I’m strong enough to push the pedal hard. 

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Has it always been this way, happened gradually, used to work great before, new vehicle to you, etc? 

Sometimes the pads and shoes look good/new but are a friction material that just doesn't bite hard like the old ones used to. Air in the brake lines is possible, though if you have a good high and hard brake pedal, maybe not. The sign of a bad booster is usually a very hard pedal though. Vacuum reading of engine would be nice to know as well, usually they want at least 18 in. hg . If you have a cam, that'll compound the problem.

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jft69z, I just got the car a couple weeks ago. But so far it’s been this way since I received it. There’s been been a massive amount of work done to the car. Basically every part I can see under the hood and under the car is brand-new. Even the actual brake lines are new. New doesn’t mean everything is right, I’m just saying previous owner did a lot of work and all appears to be quality work! 

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I added/edited a few things to my initial post that may be worth considering. I was updating it during your reply.

If it's all new to you, I'd start with the basics first. I'd probably bleed the brakes real good, make sure the rear shoes are adjusted properly to eliminate extra slop/travel too.

Everything in the pics look clean. We like lots of pictures around here too, so take a few more of the rest of the car, lol. Oh, and welcome to the best forum/group of people on the internet. You'll find plenty of help here, all without drama or attitudes.

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Yeah, it does have a cam. And I hear you on the pedal indicating the booster may be bad, but it does hold whatever vacuum it’s creating. I’m kind of thinking it just might be less than the 18lbs. I don’t have a vacuum gauge I can test it with to see what it’s pulling. I’ll see if I can get one from my parts store. 

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A cam will definitely cause issues if it's aggressive enough. A vacuum canister may help a bit, or an electric vacuum pump would do the trick....if the engine vacuum is that low. Get some data first, then go from there. Some may suggest a 'Hydroboost' unit, that replaces the factory style booster. Uses the power steering pump for pressure, like heavy duty trucks have. They work, but not exactly pretty, or stock looking. My car came with one, I replaced it with a GM unit and a Leeds Vacuum Pump.

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Thanks you guys! That gives me some ideas to look at. Going to start with a gauge so I can get a reading and adjusting the drums/shoes. I don’t imagine the parking brake has been used a lot. I can get into the habit of using it to keep the rear brakes adjusted afterwards. Also, I can definitely bleed the lines and make sure there’s no air. I’ll report back in a couple days when that stuff is all done. Again, love the group and appreciate your help! 

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The original rubber hoses at the wheel end of the system may look fine, but old rubber loses it's strength over time and may be bulging when you apply the brakes..... 

You could also check the push rod to see if it's not been set at the right length. 

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There are a lot of good ideas here.  Just because all of the parts look new does not always equal that they are good, it just looks like they are new.  If the booster is new the finish looks odd, usually they are plated rather than black. 

The booster would be my first pick.  Scott mentions the push rod which is a possibility but I thought if it was the wrong length I would think it may different symptoms.

I would also not rule out proper bleeding of the brakes.  I thought air in the line would create spongy pedal.

I was wondering if maybe collapsed or clogged lines.

Have you taken it out onto a road that is gravel covered and done some braking and look at the skid marks to see if all 4 tires are locking/dragging gravel.  If you have brakes not locking it may indicate bad brake line pressure or bad calipers etc.

Bottom line, don't trust things that look new.  We all know that nobody has ever received a bad part or two... or even three

rob

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Thanks Rob! I haven’t done the gravel test but I sure can try that. There are oodles of gravel roads where I live! Also, I sent you an email several days ago. I’d like to pay my dues. Aaron D. told me to get hold of you. I’m in Utah and I’d like to attend the Western Meet in OR this year. 

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34 minutes ago, RazzNdazz said:

Thanks Rob! I haven’t done the gravel test but I sure can try that. There are oodles of gravel roads where I live! Also, I sent you an email several days ago. I’d like to pay my dues. Aaron D. told me to get hold of you. I’m in Utah and I’d like to attend the Western Meet in OR this year. 

Congrats on the new membership ( it will get done). You can send him a private message also. 

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33 minutes ago, RazzNdazz said:

Thanks Rob! I haven’t done the gravel test but I sure can try that. There are oodles of gravel roads where I live! Also, I sent you an email several days ago. I’d like to pay my dues. Aaron D. told me to get hold of you. I’m in Utah and I’d like to attend the Western Meet in OR this year. 

Ryan, I did respond to your email of June 23rd, I am not sure why you did not get my response.  I have sent you another email with the information you want but I will also post it here.  This information is also found in the very first post in the New Members.  

Here is that information.  You have already completed the very first thing on the list so you need to do the second and third items on the list.:  

REGISTERING TO POST ON THE CLUB WEBSITE:

Anyone can come onto the boards and read posts in many areas of the boards here.  If this is you but you would like to start responding to posts your would need to "Sign Up".  You would go here to do that: https://www.firstgenmc.com/forums/index.php?/register/ and once you have filled out all of the required information such as Legal Name, Location, and Occupation properly and then you will need to respond to an email and after that one of our administrators will approve your access to post.  When that has happened you will be a "Board Member" but not an actual "Club Member".

 

BECOMING A DUES PAYING MEMBER:

If you decide you would like to become a dues paying member there will be a couple extra steps.  Please copy the below information and email it to Rob Peters at rob29ford@aol.com 

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Thanks

rob

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1 hour ago, Rob Peters said:

There are a lot of good ideas here.  Just because all of the parts look new does not always equal that they are good, it just looks like they are new.  If the booster is new the finish looks odd, usually they are plated rather than black. 

The booster would be my first pick.  Scott mentions the push rod which is a possibility but I thought if it was the wrong length I would think it may different symptoms.

I would also not rule out proper bleeding of the brakes.  I thought air in the line would create spongy pedal.

I was wondering if maybe collapsed or clogged lines.

Have you taken it out onto a road that is gravel covered and done some braking and look at the skid marks to see if all 4 tires are locking/dragging gravel.  If you have brakes not locking it may indicate bad brake line pressure or bad calipers etc.

Bottom line, don't trust things that look new.  We all know that nobody has ever received a bad part or two... or even three

rob

Hey Rob, When I first swapped the booster, I didn't set the rod long enough, and the pedal hit bottom before the piston was fully engaged in the booster.

Gave it that really stiff feel while not fully pressurizing the lines. 

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4 minutes ago, Scott S. said:

Hey Rob, When I first swapped the booster, I didn't set the rod long enough, and the pedal hit bottom before the piston was fully engaged in the booster.

Gave it that really stiff feel while not fully pressurizing the lines. 

Good Deal!!

rob

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Get, borrow, steal a vacuum gauge and see what vacuum the engine is producing. 

Is the first usage of the brakes normal then hard on the 2nd, 3rd etc uses? Or hard all the time? If hard all the time, not knowing the vacuum your engine is producing I would say the booster is bad. 

You could also let the car run for a little while, to build up vacuum in the booster, shut the car off and remove the check valve from the booster and listen for the vacuum/air exchange. If none, check that the check valve is working or installed in the correct direction. If that's all good, again the booster is most likely bad. 

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I just picked up a gauge from my local parts store. Going to check it tomorrow. I did those very tests you’re speaking of last night and the pedal behaved as if the booster was not leaking. It’s a hard pedal every time; 1st, 2nd, etc.  My dad was searching for available boosters for the car online and said there was 2 different ones that fit it. One has less boost than the other. But apparently they have the same bolt pattern and look the same from the outside. They have different diaphragms. We are thinking maybe this car has the weaker one. Like the booster is operating but perhaps not generating enough assist. Not certain but we think that may be what’s going on. 

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If the pedal is hard all the time, the booster is leaking internally. Bad booster.

If you had a normal pedal the first application, then a hard pedal after that, I would say the engine is not making enough vacuum. 

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Do you know if the master cylinder is original? If it was replaced with one that has too large of a bore, it will cause the pedal to be really stiff. Even with a working booster. Just a thought.... I got messing around with my brakes and I was amazed at how big of a difference the master cylinder bore size makes.

 

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3 hours ago, GatorDog72 said:

 If it was replaced with one that has too large of a bore, it will cause the pedal to be really stiff.

 

Monte's already come with 1 1/8" bore, pretty much the largest of that type, I think (for a standard replacement).

 

I had the choice to go smaller (1" & 15/16") when I put the rear discs on and chose 1" due to lower vacuum, stock booster, etc.

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