braking system

[Deleted member 21878]

pretty much finished up the front suspension today with mounting the hubs. All went pretty well.

Tomorrow i plan to start on the front calipers and then running the rest of the brake lines. couple of questions:

1) the parts pictures show what they call "distance pieces" (#36 on the Moss Master cylinder page) for the master cylinders. i have new M/C's for both the brakes and clutch. But when i pulled my old M/C's off, only the clutch had the pieces there. are they required for both? and their purpose?

2) i have also read about shims to center the calipers on the rotor. but they do not show up on Moss. anyone use anything else for this? are these usually pretty close? i did not pull my calipers off but i do not see anything that looks like shims in any of the boxes. probably got tossed at some point years ago. but if i need them, i may as well do it while i am here.

Thanks

 

[steveg]

...
1) the parts pictures show what they call "distance pieces" (#36 on the Moss Master cylinder page) for the master cylinders. i have new M/C's for both the brakes and clutch. But when i pulled my old M/C's off, only the clutch had the pieces there. are they required for both? and their purpose?

2) i have also read about shims to center the calipers on the rotor. but they do not show up on Moss. anyone use anything else for this? are these usually pretty close? i did not pull my calipers off but i do not see anything that looks like shims in any of the boxes. probably got tossed at some point years ago. but if i need them, i may as well do it while i am here.

Thanks

1) these are used to adjust the clearance of the pushrod, since it's non-adjustable. I made them out of heavy gasket paper. Then I went to an adjustable pushrod and clevis (from Pegasus).
2) you can use washers from the home store, as long as you measure them and they are the same thickness. Grade 8 washers are uniform. I moved one of my rotors by inserting a home-made sheet steel shim between the hub flange and inside the "hat" of the rotor. Just don't use aluminum.

PS - the rotors rust quickly. I'd paint the hub and the inner part of the rotor out just into the area that will be scrubbed off by the pad.

 

[Deleted member 21878]

Steve thanks. here hoping i do not need to move the rotor out... ha.

hmm, i need to read a little more on the installing of the M/C's. not quite there yet. but was looking thru the parts for things i may need to have for the job.

 

[steveg]

Steve thanks. here hoping i do not need to move the rotor out... ha.

hmm, i need to read a little more on the installing of the M/C's. not quite there yet. but was looking thru the parts for things i may need to have for the job.

I recently bought a Classic Gold master cyl and it appeared the pushrod shaft is 5/16" diameter. Therefore you could thread it and install a forged clevis (with locknut) from the hardware store or Pegasus. Then you could adjust it to the correct length without the packing pieces.

 

[healeyblue]

Our clutch also only has "distance" pieces.

 

[Rob Glasgow]

Drone Dog, I noticed you have a red stripe painted on your front spring. According to my restoration book, the hand painted stripe on a BT7 should be green. When I cleaned my original springs, there was evidence of green paint, so I repainted them green. Not that it makes much difference to the way the car performs....
I did paint the bonnet latch spring stripe red though.

 

[Deleted member 21878]

Rob: according to my book the stripe color changed in June of 1960 to red. My springs had remnants of red paint on them. don't think i got exactly the right color of red but it looked pretty close.

Steve, read thru the manual again last night. i could not find where it says how to determine the right length for that rod. How do you determine it? mine says to just install the distance pcs.

seems to me, in one of the boxes out there, i have a new M/C that is for a BJ8. for some reason i think that one looked like it could be adjusted. i did not use it because i was afraid it might have a different travel set up or something. but maybe that is why the PO bought it. those distance pcs are not very thick. Wonder how much it changes. i could see the clutch needing something more than the brake since it seems the clutch pedal would have more travel.

Nice tip on painting the rotor. Thanks. have to see if i have anything that can take the heat.

 

[steveg]

Moss & Girling pushrods. Both 5/16" dia.

 

[steveg]

Rob: according to my book the stripe color changed in June of 1960 to red. My springs had remnants of red paint on them. don't think i got exactly the right color of red but it looked pretty close.

Steve, read thru the manual again last night. i could not find where it says how to determine the right length for that rod. How do you determine it? mine says to just install the distance pcs.

seems to me, in one of the boxes out there, i have a new M/C that is for a BJ8. for some reason i think that one looked like it could be adjusted. i did not use it because i was afraid it might have a different travel set up or something. but maybe that is why the PO bought it. those distance pcs are not very thick. Wonder how much it changes. i could see the clutch needing something more than the brake since it seems the clutch pedal would have more travel.

Nice tip on painting the rotor. Thanks. have to see if i have anything that can take the heat.

I used normal paint last year and it looks fine. They don't get that hot in everyday driving.

 

[RDKeysor]

Further to the discussion of packing pieces, I assume we are talking about the pieces that you may find between the clutch or master cylinders and the firewall. I found just one such aluminum piece shaped to the outline of the mounting tabs on an early master cylinder. Forgot to reinstall it and didn't realize its function. On another topic, the Lucas-marked larger master cylinder I describe in my ongoing post about brake bleeding has a yoke that threads onto the push rod, thus providing some adjustment. I did end up adjusting it after the installation.

It only briefly crossed my mind that I could convert it to work with my new BN7 standard MC to compensate for the low pedal I've whined about. Only briefly!

 

[Rob Glasgow]

Drone Dog, that explains it. My BT7 was built in March 1960 so right before the change to the red stripe. So you got it correct. I also found a yellow spot of paint on the side of the steering box that I'm not sure means anything. Maybe indicated the unit had oil installed. It's fun finding these various markings on the car that were put there during assembly. Makes you feel that some real folks were part of the assembly process. I tried to replicate those markings when I restored it. Even added my name and date to the wooden panel on the dash pad so someone it the future will know who worked on the car in 2016.

 

[Deleted member 21878]

Steve
see your post on the 5/16" pushrods. but i guess i am a little thick. not sure i get what length they should be from that. i guess i am asking "exactly what do the spacers do?" are they there to keep the piston in the M/C from bottoming out? how do i determine if i need them and how many i need?

are they to allow some play in the pedal?

 

[Rob Glasgow]

I always thought the only purpose of the spacers was to adjust the height of the pedal. If you use the spacers, the pedal will be lower to the floor. If they're are not used, the pedal will be higher. The spacers only move the pedal height by about 1/4" or so. I can imagine if the brake pedal was a little lower, it might make 'heel and toe' shifting a little easier. But this is just a guess.

 

[steveg]

I always thought the only purpose of the spacers was to adjust the height of the pedal. If you use the spacers, the pedal will be lower to the floor. If they're are not used, the pedal will be higher. The spacers only move the pedal height by about 1/4" or so. I can imagine if the brake pedal was a little lower, it might make 'heel and toe' shifting a little easier. But this is just a guess.

That makes sense. Taking it to an extreme - if you put a 1/4" spacer in, it would move the MC forward by that amount and the retaining washer on the pushrod would pull the pedal forward by - a large amount.

Having said that, IMO the adjustable pushrod would also allow you to adjust the pedal height. If you already have this installed, the adjustment becomes a matter of loosening the locknut and twisting the pushrod to change the pedal position.

I can see why the factory did it with the distance pieces and fixed pushrod - cheaper and they made them all the same anyway. People like us might want to adjust them.

Norm Nock's book talks about welding up worn-out holes and re-drilling them - seems like a huge effort compared to a threaded shaft and clevis fork.

 

[Deleted member 21878]

Ok. Now I understand. Thanks.