I need a measurement
Thread Starter
Drifting
Joined: Aug 2007
Posts: 1,924
Likes: 6
I need a measurement
I am trying to determine the distance from the backside (mount to firewall side) of the brake booster to the hole in the cleavis (the u shaped thing that 'pins' to the brake pedal arm)
The reason I need this is because I have converted my 81 from automatic to standard using all parts from a 79 C3 (except the brake booster). However, when I was installing the brake booster back into the car to attach to the newly installed pedal assembly, the clutch sits up where it should, but I have to push the brake pedal toward the floor about 2 inches to get the pin to line up with the cleavis and brake pedal arm.
So I removed the booster, and am suspicious that the wrong booster is in it or bubba did a swap before I owned it or the 81's brake booster has collapsed inside (I dont know the mechanics of whats inside a booster).
On the one I removed, it is 5 3/4 inches from the booster mount face to the hole in the cleavis. And I need to know from anyone that may have a booster out of a c3 lying around what the distance is, or if someone with a factory manual 4 speed could measure under the dash for me from the firewall to the pin.
-TIA
The reason I need this is because I have converted my 81 from automatic to standard using all parts from a 79 C3 (except the brake booster). However, when I was installing the brake booster back into the car to attach to the newly installed pedal assembly, the clutch sits up where it should, but I have to push the brake pedal toward the floor about 2 inches to get the pin to line up with the cleavis and brake pedal arm.
So I removed the booster, and am suspicious that the wrong booster is in it or bubba did a swap before I owned it or the 81's brake booster has collapsed inside (I dont know the mechanics of whats inside a booster).
On the one I removed, it is 5 3/4 inches from the booster mount face to the hole in the cleavis. And I need to know from anyone that may have a booster out of a c3 lying around what the distance is, or if someone with a factory manual 4 speed could measure under the dash for me from the firewall to the pin.
-TIA
Instructor
Joined: Jun 2007
Posts: 129
Likes: 7
From: dallas pa
i just did the same swap and purchased a new booster as it was too much work to take a chance on a 27 year old part, the new booster came with a standard plunger and a longer plunger, i still have the longer one and if this is what you need you can have it, i will try to find the instructions explaining the difference but i may have pitched them
Racer
Joined: May 2006
Posts: 264
Likes: 0
From: Fort Myers, Fl / St. Paul, Mn
I have a 72 and my brake pedal is about 2 inches closer to the floor than the clutch. If that isn't right maybe we can both get some info here. I have replaced the booster and there was no change.
Instructor
Joined: Jun 2007
Posts: 129
Likes: 7
From: dallas pa
i just measured the plunger rod with out a clevis it is 4 inchs to the mounting face of the booster, not to confuse things the plunger rod i spoke of earlier goes into the master cylinder side, i do have a complete 1980 booster and if you pay the freight it is yours.
Thread Starter
Drifting
Joined: Aug 2007
Posts: 1,924
Likes: 6
heya BT57, thanks for the quick response. How do you remove the plunger from the booster? Mine just spins and is limp (wont "stay")
are your pedals 'even' with each other?
this is confusing the crap out of me.
are your pedals 'even' with each other?
this is confusing the crap out of me.
Melting Slicks
Joined: May 2001
Posts: 2,812
Likes: 4
From: Gig Harbor Wa
The boosters are the same between manual and automatic and with the years you are talking about.
Also, I am pretty sure the clutch pedal is adjustable.
Does the brake pedal sit lower than it did before the swap? Or is it just low compared to the clutch pedal?
Also, I am pretty sure the clutch pedal is adjustable.
Does the brake pedal sit lower than it did before the swap? Or is it just low compared to the clutch pedal?
Thread Starter
Drifting
Joined: Aug 2007
Posts: 1,924
Likes: 6
Thanks, but that doesnt look like the rod on mine at all.
mine looks like this.
But in searching the 'bay it appears there is a 68 to 76 version and a 77 to 82 version. I'm trying to find out what the difference is. Thinpockets, do you have a problem with your brake lights? because, after I installed everything yesterday, the light switch from the 81 couldnt make contact with the off paddle on the 79's pedal cluster.
mine looks like this.
But in searching the 'bay it appears there is a 68 to 76 version and a 77 to 82 version. I'm trying to find out what the difference is. Thinpockets, do you have a problem with your brake lights? because, after I installed everything yesterday, the light switch from the 81 couldnt make contact with the off paddle on the 79's pedal cluster.
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Melting Slicks
Joined: May 2001
Posts: 2,812
Likes: 4
From: Gig Harbor Wa
The difference between early and late is the pushrod that goes between the master and booster is longer for early. Also late is cad plated and early is painted black. Internally they are the same.
Racer
Joined: May 2006
Posts: 264
Likes: 0
From: Fort Myers, Fl / St. Paul, Mn
Now that you mention it, there was a problem with the brake light switch. It is so close to the top of the pedal travel that the brake lights would stay on sometimes. I was able to adjust it but it's still close. It doesn't seem right that it should be that close to the top - unless the pedal isn't in the right position. I also have a problem that the brake pedal travel is lower than the gas pedal when they start to grab. If I have my foot on both it gets hairy stopping. I'd like to have the brake pedal higher than the gas.
Thread Starter
Drifting
Joined: Aug 2007
Posts: 1,924
Likes: 6
I gave the automatic pedal assembly to the guy I bought the 4 speed setup off of and that was in 2005. The project stalled for a year while I was off doing other stuff. (06 MustangGT) So I really can't remember if the pedal was noticeably low (as an automatic). I think I just assumed it was normal.
As far as the clutch goes, everything from the pin on the pedal to the z bar to the throwout bearing arm lines up perfectly with the adjuster nuts just about midway on the rod, s I'm thinking where it sits, should be right. So I'm using the clutch pedal as a guage that the brake pedal is lower (by about 2 inches)
As far as the clutch goes, everything from the pin on the pedal to the z bar to the throwout bearing arm lines up perfectly with the adjuster nuts just about midway on the rod, s I'm thinking where it sits, should be right. So I'm using the clutch pedal as a guage that the brake pedal is lower (by about 2 inches)
Thread Starter
Drifting
Joined: Aug 2007
Posts: 1,924
Likes: 6
my guess is then you DO have the clutch bumper stop that keeps the clutch pedal from coming up too high like this one I found while searching ebay for pedal pictures
Racer
Joined: May 2006
Posts: 264
Likes: 0
From: Fort Myers, Fl / St. Paul, Mn
I don't have the 'booster pedals' but my clutch definitely rises to a higher level like that. I'm going to try and get under there today and see if I am missing a bumper on the clutch pedal but considering how low the brake pedal is when it is all the way up, I'm hoping the pedal to booster link is the problem.
Thread Starter
Drifting
Joined: Aug 2007
Posts: 1,924
Likes: 6
In my assembly manual for my 81, it references the clutch pedal bumper location, but doesn't actually show what it looks like or how it mounts. It could be as simple as a press on foot. It mounts on the inside of the housing that holds the pedals, in the left front corner (looking at it from the driver seat)
When the clutch pedal is in driving, sitting position, the arm of the pedal rests against the stop. If it's a cheapy thingy, I may drill a hole for a simple nut,bolt and make my own stop.
I see I will need to raise the adjuster in the engine compartment on the threaded rod, but it is apprx mid way right now, so there's room to move up the rod.
or we could get a set of those booster blocks and split the cost since we both really only need one each
When the clutch pedal is in driving, sitting position, the arm of the pedal rests against the stop. If it's a cheapy thingy, I may drill a hole for a simple nut,bolt and make my own stop.
I see I will need to raise the adjuster in the engine compartment on the threaded rod, but it is apprx mid way right now, so there's room to move up the rod.
or we could get a set of those booster blocks and split the cost since we both really only need one each
I don't have the 'booster pedals' but my clutch definitely rises to a higher level like that. I'm going to try and get under there today and see if I am missing a bumper on the clutch pedal but considering how low the brake pedal is when it is all the way up, I'm hoping the pedal to booster link is the problem.