4AD front brake spring placement

[StLouisSinger]

I have no diagram of properly installed front brake springs. Mine are set up so the springs run from the backing plate to the brake shoe. The one parts manual I have clearly shows the upper shoe connected to the lower shoe not the backing plate. But the holes on the shoes do not line up, to make this happen I would have to wrap across the hub. Anyway I know I have the shoes in correctly becuase the adjustment pins line up with the cams and there is no other way to install them. I'm just having brake issues with front imbalance of braking, I have blead system and checked cylinder movement. I was thinking the springs were in wrong but can't see how else they can be insalled. Maybe I have the wrong shoes? It is a 52 4AD with the two brake cylinders on each wheel.
My next step is to turn the brake drums. If the drum is found to be too out of whack is there a place to get a new replacement. I spent all evening setting up the linkages corerctly and the back brakes are good and the front left is good but the front right is not keeping up. Any help would be appreciated.Thanks in advance.
Tom

[Paul Bouchard]

Hi Tom,

Here is some info from the "Scientific Magazines Service Manual".

Paul

[StLouisSinger]

Thanks Paul. I searched like crazy all over the internet but I could not find any picture like that. That looks like the way mine are set up. Which is good and bad. My next step is to have the drums turned.
Thanks again for the assistance.
Tom

[Paul Bouchard]

The information is from a book published in Australia (Scientific Magazines) that coveres the Nine Roadster, 4A and 4AB. Since the brakes and front suspension on the 4AB is the same as the 4AD I thought that it would work. I scanned the book (long out of print) and sent it in to the club librarian. If you send him a note he can arrange to get you either a hard (paper) copy or a soft (PDF file) copy. His contact information is listed on the inside cover of the club magazine. If you do not have it handy, e-mail me and I will pass on his coordinates.

Paul
paul_bouchard@yahoo.com

[Peter McKercher]

You may also find our club website useful where you will find a 4AD parts manual.

From the Home page, go to the Technical and Miscellaneous section and you will find a drop down menu with all sorts of useful information. Select Parts Manual - 4AD.. To make it easy, here is the link.
http://www.singercars.com/4ax/4ad_parts.html

[BRG]

Do not know what type of imbalance you have on braking. Could have a problem with the front rubber hoses. Age will affect the hoses. If Dot 3 has been used will cause swelling and a poor fluid transfer to front wheel cylinders. Dot 4 or Castrol LMA brake fluid (preferred). The club does stock the front hoses if needed.
BRG

[StLouisSinger]

My fahter-in-law replaced the rubber hoses about 6 years ago (when he owned the car) and he had been using Dot 3 with the new hoses. I think back then the hoses were from either Moss or Kipp. We assumed DOT3 was adequate for the modern hoses. At the same time I helped him replace the master cylinder and all 4 wheel cylinders and these parts have had little use since then. The car pulls pretty hard to the left (drivers side). And it jerks a bit at first, leading me to belive the left side is engaging early. I have blead the lines. I have greased the tips of the shoes and any contact points with high-temp grease, I have observed that all wheel cylinders are functioning, There is little difference in brake pad thinckness between the two sides. I have adjusted and readjusted the brakes. I follow the instructions in the manual. I raise the wheels, then tighten the 2 adjusting nuts until contact is made and then back off a bit to allow wheel to spin freely. This evening I took my wrenches with me on a test drive and tried tightening the right side and loosening the left side and I had some improvement but the brake pedal travel is looser now and the looser set up makes the brakes a bit grabby. You think fluid and hoses really will make a differnce?
Thanks again,
Tom

[Paul Bouchard]

Hi Tom,

Being a "rod brake" man myself, I am not a pro when it comes to the 4AB-AD braking system. However I do remember my 1975 Honda Civic that had the same problem and it was due to a sticky piston. Dave has a good point with the LMA brake fluid considering its low moisture aspect. Could it be possible that you have some rust or contamination in one of the pistons/cylinders in the right (slower) side?

Just thinking out loud...

Paul

[Peter McKercher]

Is it possible that one shoe has been contaminated with brake fluid at some point and not replaced when the cylinder was repaired

[BRG]

I would not use Dot 3 as it tends to swell up natural rubber seals. If you rebuilt the master and wheel cylinders with Girling rubbers I would definately change fluid to Castrol LMA this has no chemicals that attack natural rubber seals. Dot 3 will disolve rubber. One thing to try is swap the shoes side to side and see if the pull changes to that side then it would be the shoes. Another thing to consider is front end wear could cause a pull if something is loose or wore out.
BRG

[StLouisSinger]

I tried a few more things today. I considered the flexible hoses being the problem so I switched them. There was no change.
I also disassembled and cleaned out the wheel cylinders on the lagging side. The cylinders were clean, and the seals looked like new. After I reassembled the cylinders I noticed some improvement in braking and a slight reduction in pull to the side.
Switching the pads is a good idea, it would be a lot easier than switching the hoses. I was so out of it tonight, when I went to
bleed the left side of the car I reached for the bleed nipple and found it was broken off so I put my tube on the remaining nub and started to turn it and the whole thing broke apart. Then I realized I was putting the bleed tube on the threaded end of a screw and I was undoing one of the nuts that holds the wheel cylinder in place. Man am I out of it.
Thanks for the help everyone.
Tom