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Poor brakes, but new?

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Go_Dogs_Go

Go_Dogs_Go

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I am restoring a 66 AH Sprite and I'll post pictures real soon. My first LBC and it looks so good. It has the old style master cyclinder as opposed to the dual can version. I replaced the front disk calipers and rotors. I replaced the rear cylinders, and shoes. The rears seemed to bleed well. The front bled but the adjuster screw really allowed the vacuum bleeder to suck a lot of air too. But I got clean fluid from them eventually. Before the rebuild, stopping required a lot of forethought and pumping. I just tested the system and the brakes pump up after several pumps but then you have to do it again in a very short time if you want to stop again. What would cause this total brake fade? The clutch sharing the same master cylinder does not engage until the pedal is practically on the floor. Is this related? If not then can the clutch pedal be adjusted to engage without all the free play?

Your help is much appreciated. I could not find this exact topic so forgive me if I missed the same question.
 
I'm running the same kinda cars and it sounds like you still have air in the system. The dual master can be a pain to bleed sometimes. I blame it on that loop of tubing running above the master. The clutch symtom sounds like air there as well.

KA
 
It sounds like you may have too much free-play of the peddle before it touches the piston (possibly on both sides).
Be sure that the pistons are returning all of the way to the front and that the pushrods are very close (but not touching) them. You should only have about 1/2" of freeplay (where your foot touches the peddle) before the peddle starts to move the piston.
Another question- are you using DOT3 or DOT5 (silicon) brake fluid?
BillM
 
My guess would be rear drum adjusters too loose.

JACK
 
First, Welcome!

Please post some pictures and info about your car as you are able.

All of the above comments are good ideas. In particular, I always end up bleeding my master cylinder at the lines going into it (as well as at the brake drums and disks). To do this, have someone pump and hold the brake pedal down while you loosen the brake lines going into the master cylinder. Loosen them *just* enough to allow air/fluid to escape and re-tighten before the pedal is released. You may have to repeat this several times.

This is obvioulsy a messy job and brake fluid eats paint, so protect the surrounding painted areas with rags.
 
Be sure to replace the brake hoses, all have a tendency to collapse over the years and will not pass fluid. IF they are older than 10 years and there is a date code on the hoses, replace. Parts are cheap, your life isn't.
 
I've never been able to use those vacuum bleeders. As you say, it sucks in air around the threads of the bleed nipple. I'd first try bleeding the brakes the old fashioned way, with one person working the pedal and the other at the wheel. I'll bet that does it.
 
Great input! Thank you all.
I re-bled the front brakes using a helper and that helped a lot. I will bleed the master cylinder as suggested and sometime this winter replace hoses with braided lines. BillM, I will have look in the manual and see how to do what you are suggesting because I would guess it needs to be done.

I should post some pictures here, but for now here is a link to my car. All work done by me in 8 weeks. I am tired but excited!

Thanks for your help!!
https://www.facebook.com/album.php?aid=58915&l=0e181650dc&id=1636837452
 
Car looks super! Are the red springs the new ones? Why so much taller? Wondering if you didn't end up with 1500 springs by mistake (ask me how I know?).
Looks great.
Maybe the master is leaking internally too, is it rebuilt?
 
I agree, wrong spring, Wonder what it looks like from the side?
 
Bleeding can be a bitch and it does sound like air in the system is your problem. I definitely would not use a vacuum bleeder since it can easily introduce air into the system around the bleed nipples. I would say that it is well worth your while to get an inexpensive pressure bleeder instead. The eezibleed is one brand (uses air pressure from the tire) and there are others out there that are reputedly better.

Also, make sure that you have the caliper bleed screws in the right holes. I can't remember how it is on the spridget but my MGB calipers shipped with the bleed nipples in the wrong holes (i.e. the ones at the bottoms of the calipers). If I had left them there I would never have been able to bleed out all the air.
 
As far as bleeding techniques go, I've tried a bunch:

EZ Bleed
MityVac
Shooter Reverse Bleed
Some crap thing from Advance

Only the EZ Bleed worked but even that is a PITA - you need to dig out your spare tire and half deflate it. Then you are bound to get fluid coming out the master cylinder and all over the engine bay.

The best method by far is two guys and a six pack.

The last time I was visiting the brother-in-law (he is a car mechanic) we done his car and he didn't even bother with the tube and jam jar. Just let it loose on the floor and then a quick clean up with paper towel. Works very fast and gives a rock hard pedal.

Cheers!
 
Hmm. You have me wondering. But MOSS has not sent any bad parts so far and basically everything you see is MOSS. According to the VIN number it is the right pair of springs. MOSS lists two sets based on VIN and my VIN is HAN8L64181. I got the parts listed as 265-610 at this link: https://www.mossmotors.com/Shop/ViewProducts.aspx?PlateIndexID=29294#46

Could it be that the prior springs were frm a lowered front end or that they sagged? After all the work I am not going to be happy about replacing them. THe difference was about an inch in spite of the view in the picture. Maybe 1.5. How serious is this difference if I did get 1500 springs?

Man I really do not want to pull that front end apart again....
 
I went through 3 sets of springs before I ended up going with BE Springs for my '68. I had an off road Sprite and raising the center of gravity does affect handling, There are tricks to replacing springs. It can be done in just a few minutes with long helper bolts to decompress and compress the spring.
 
Bugeye front springs:

9.4 in long or 244 mm

1275: 9.59 in long

1500: 9.85 in long

rate 271 lbf/in for all of them.


now you know. Hope you measured before putting them in or measure the old ones and see what you had.

In years past I have been known to cut plymouth springs to the bugeye length and use them as they had a higher spring rate which allowed me to corner in a drift useing the throttle for control. However, we won't talk about that, was never caught.
 
Thank you all for your input. Jlaird, unbelievably the springs may be the only parts I did throw away. And for some reason only the front ones. I have a local shop that specializes in LBC so I'll let them look. I'll also post a picture soon. The manual bleeding of the brakes worked well.
 
I have the 1500 springs in my '63 (the tag from Victoria British was still on them and readable, 20 years later) but my car sat so high in the front I lowered it. Word was (is) some suppliers shipped the 1500 springs to those ordering the shorter ones.
old thread on it
 
How tall are a new pair of 1500 springs? And 1275?
 
If you don't want to change springs you can lower them with a stack of washers and some longer bolts on the spring pan's.

KA.
 
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