Brakes: Brake pedal sticking on 64

[rbigcal]

Now I have ran into another problem on my 64 Wagonaire. Brakes are barely working and I discovered that brake pedal is sitting too low causing a lot of slack before the rod to the booster moves. My first thought was maybe the lever that pedal rod and booster rod was installed backwards or something, but looking at parts diagram I see that holes are centered and lever is straight , so that rules that out. Rods are not adjustable and I believe I replaced the return spring. Is there any chance that the pivot bolt that fastens to the pedal is supposed to be ecentric ?

[StudeRich]

So this is a '64 Lark Type Disc Brake Car with the Bendix Mastervac P/B Booster?

You know there are:

Dual Master Cyl. Push Rods for Drum Brakes

Push Rods for Disc Brake Cars

And probably Rods for Power Drum Brake Cars.

If someone has done some "conversion" work on this car, incorrect repairs etc. there is your answer, Wrong Push Rod!

[karterfred88]

Now I have ran into another problem on my 64 Wagonaire. Brakes are barely working and I discovered that brake pedal is sitting too low causing a lot of slack before the rod to the booster moves. My first thought was maybe the lever that pedal rod and booster rod was installed backwards or something, but looking at parts diagram I see that holes are centered and lever is straight , so that rules that out. Rods are not adjustable and I believe I replaced the return spring. Is there any chance that the pivot bolt that fastens to the pedal is supposed to be ecentric ?

Not that I think it's your problem, but yes, the bolt going through the pedal arm is eccentric, loosen the lock nut and rotate to adjust pedal height and tighten the nut. It could have loosened and swiveled lowering the pedal height. If they "still barely work" it's time to check the system , including booster. If the pedal is "hard as a rock" like you are stepping on a brick, it might be the booster, rod in wrong hole on the pedal, also and I'm not certain if the Lark uses the bracket between the body and the booster, if it has a lever arm in it, check the pin through the tube the arm is welded to is not binding. Have someone depress the pedal while watching the square head of the pin, if the square head moved and then the arm stops moving, pull the bracket off take it apart and get the pin to allow the arm to move freely. On my Avanti, it somehow bound up so bad, that a prior owner BENT the brake pedal trying to stop. I had to use a torch to heat the tube to extract the pin, hone out the tube and put a replacement pin in so full range of the arm would be there to depress the master sufficiently to stop. Good luck.

[rbigcal]

This did not have eccentric bolt, but maybe it is supposed to. The main problem seems to be the pedal is sticking before it goes all the way up. I thought I must have reassembled something wrong, but doesn't seem to be the case. This afternoon I took the booster off and found a tapered spring in the backend of the booster that holds the pushrod out that was kinda screwed up and looked like it was causing rod to catch, so I repaired that and thought problem was solved. Now when I put the top pin to booster rod in , I'm back to something catching and pedal sticking partially down again. Linkages are all clean and free. Another mind boggling case here. I think this car is named Christine. lol

[karterfred88]

Can you pull the pedal all the way up? Shoot some pictures and attach under "go advanced" "manage attachments" Nothing should be "falling out" of the back of the booster, unless it fell apart inside. Take some pictures of your booster-M/C and the rod to the pedal, maybe we can better diagnose it. From Bob Johnstone's site it appears you do have the adapter bracket with or without disc brakes 1112-5 is the pivot discussed by me before-it will stop the pedal from returning and going far enough to apply the brakes right. If the back of your booster had the "cap" fall off that the rod goes through--you need a rebuild-it helps hold the vacuum. Easy test- pull the vacuum line from the booster, suck on it, if you can keep pulling air out --it's toast.

[rbigcal]

I did not mention anything "falling out" of booster, when you pull the pushrod out and remove the rubber boot you see a metal cap that retains felt seals and the spring is behind that, it had jumped over the shoulder it sits against on the pushrod is all. I reamed out a thin washer and put behind the spring so that will not happen again. Apparently that had nothing to do with it. All the parts seem to be exactly like in plate#11-21 in the chassis parts manual. And yes pedal pulls up by hand. I can not find any place where anything is binding or rubbing. I guess I will once again have to pull booster off, but with booster on bench it seems to work fine.

[karterfred88]

can you pull the pedal up easily? Did you remember the 4 spacers between the booster and the mount bracket, mount it on the firewall with the booster/MC up from the hole in the firewall, pedal rod to lower hole nearest pivot, booster rod at the very top of the lever? If you disconnect the booster rod at the adapter lever will the pedal then go all the way back up by moving it by hand? Sorry the attached is so rough but it should give you a visual as to why the pedal cant go all the way up or down-hope it helps. By the way, the pin with the square head will move okay off the car, when the bracket is bolted in place the head engages tangs so it can't spin, so it may seem ok on the bench-pull the cotter pin and try to slide it out of the tube-can't hurt to lube it even if it isn't binding.

[rbigcal]

All linkages were bead blasted and painted etc. Lubed it all upon assembly. I checked it out more this morning, brake linkages work very smoothly when disconnected from booster. Now I have found that booster is leaking, so I sent it off to Booster Dewey for rebuild. Booster checked out good originally so I cleaned it and painted it to perfection. Brakes worked fine when I first got the car halfway driveable, but then seemed to go downhill. I imagine the rubber in the booster seals and diaphragm was hard then took a dump after being used for the first time since who knows when.

[karterfred88]

Good luck with the booster, hope it fixes your problem.

[rbigcal]

Good luck with the booster, hope it fixes your problem.

Got booster back from re builder and brakes work great, but pedal is still very low. Apparently I must need the eccentric bolt instead of regular one. I don't seem to find new ones listed. Anybody have a good used one ?

[karterfred88]

I have one, but it's in a Lark pedal assembly I'm transplanting to my Avanti. If you can't find one from someone on here or get a new one, PM me and I'll check the one on the car is the same-if so you can have it. Don't know if the part numbers are the same. Avanti 1552039 and1552040, see if they match up to the Lark numbers. Might also try Bob "Rkapteyn" he has a huge stash of those rare parts. Try private message.

[rbigcal]

The bolt number I came up with in 64 chassis manual is 1552280 and bushing # 1552040, I have no way of knowing if that is an eccentric bolt or not. Avanti bolt might work but I have no way of knowing that either. It could be possible that somebody replaced the push rod with the wrong one too. I do know that an eccentric bolt the right size would solve the low pedal problem.

[karterfred88]

The bolt number I came up with in 64 chassis manual is 1552280 and bushing # 1552040, I have no way of knowing if that is an eccentric bolt or not. Avanti bolt might work but I have no way of knowing that either. It could be possible that somebody replaced the push rod with the wrong one too. I do know that an eccentric bolt the right size would solve the low pedal problem.

Well I pulled the pedal to rod bolt from the Lark pedal set I have, and the bushing, it doesn't seem to be eccentric, at least not enough to be visual, whereas the one on my Avanti obviously is. Don't know if it should be or not. Check your brake section of the repair manual and see if there is mention of Pedal Height Adjustment in the brake section in the Lark repair manual like in the Avanti manual. If not start a thread "looking to buy 1552039 eccentric pedal bolt." The shaft of the bolt size through the pedal is identical so it will work for you-right or wrong.

[rbigcal]

What year of avanti ?

[karterfred88]

What year of avanti ?

Any--- the part number is the same for a manual trans or A/T since they only had one brake option. Dan at Nostolgic (248) 349-4884, he should have one, or Bob at http://avantiparts.biz/ Phil at http://www.fairbornstudebaker.com/ or Robert on here http://forum.studebakerdriversclub.c...?1010-rkapteyn
The other option would be to find or make a new rod from the pedal to the "adapter" arm. Without a Lark parts book, I wouldn't be able to locate a number for you, but it seems like there are rods for disc/drum and drum/drum and may be different with the different boosters also. Good luck-sorry mine won't work for you.
Just spent some time with the online Lark parts book. According to that if you have factory Disc Brakes you should have the eccentric bolt, if drum brakes the part number is different and may not be eccentric, the correct bolt part number is the same 1552039 for the Avanti and the Larks. If yours is not eccentric, I'd guess it was lost somewhere. The Rods for drum and disk to the adapter are also different, drum 1559726 and disc 1559938. I have no idea if one is longer than the other but may also be part of your pedal problem.
Hope that helps and doesn't just confuse you.