41 Cadillac Brakes

[robert G. smits]

Started getting my 41 ready for a local show today.  Driven on the AACA Glidden in Sept and locally in Dec.  Brake pedal went to the floor without resistance.  Checked master cylinder and it was dry.  Added fluid and still no brakes. Didn't have time to bleed but will tomorrow.  Car is original with 50K.  Boot around master cylinder rod is dry and cracked suggesting master cylinder has been there for some time.  I do not see evidence of brake fluid leaking on any of the tires.  Floor under car is oil stained from previous owner and I didn't see anything to suggest an accumulation of brake fluid.  Previous owner rebuild the wheel cylinders in 2005 and braking has been excellent.  Thoughts and suggestions appreciated.  Thanks to all.  Bob

[David King (kz78hy)]

I think you know the answer, the fluid went somewhere.  I'm pretty sure there is no power booster involved, so there is major leak somewhere.  Time to work the problem.  Inspect the drums for evidence of leaks and then work your way up to the master cylinder and reservoir.  Pulling the drums for a look will be required and I will bet you will find one very bad.

David

[robert G. smits]

Does anyone know of a source for a heave duty puller to remove the rear brake drums?  I have heard this can be a nightmare.  Thanks, Bob

[robert G. smits]

Bled the brakes today and the pedal was immediately back to normal. I sat in the car applying maximum pedal pressure for 10 minutes hoping to find a leak point.  During that time there was no pedal fade at all.  Could the fluid have evaporated slowly since 2005 without a leak?  Recommendations appreciated as I'm not sure where to go from here.  Bob

[Gravel]

Since you have no signs of leaks, it is entirely possible that the fluid level was left somewhat low after last service. The reduction of pad surface on the shoes will allow the pads to work further out, requiring more fluid to displace the wheel cylinder pistons to that point. You eventually came to the end of your fluid reserve and all it takes is a good gulp of air by the Master to give you zero brakes.

It is also possible that you have a slight seepage at one of the wheel cylinders, though most often you would see this appear as dusty/dirty spots at the bottom of the brake backing plates.

Lastly, had you still had a touch of fluid in the Master, I would have picked the master as having stiff cups that were no longer sealing properly when applied. But since the fluid was gone, that likely isn't the case.

Given that you have the boot cracking at the Master, and it has gone dry, it might be a good idea to pick up a rebuild kit and go through it at your next available opportunity.

[PHIL WHYTE CLC 14192]

Don't skimp on brakes - one of the most important features of your car. When I get a "new" old car and the brakes are even slightly dodgy I strip the lot out - i put in rebuild kits or cylinders [whichever is needed], new hoses and kunifer brake lines [in the USA you tend to favour stainless steel - this is good also] and new shoes if necessary. It'll cost you a pot more if your brakes fail.
Phil

[robert G. smits]

Thank you to everyone who replied.  I have replaced the master and all brake hoses prior to the Cadillac LaSalle National Driving Tour next week.  I will go through each wheel individually later this summer.  I purchased the 41 three years ago from a life long friend who sent it to his restorer with instructions to check and update everything prior to delivery to me.  When I inspected the car it had new radials,fanbelts and all fluids were fresh. I am ashamed to admit that because of the general condition of the car I failed to inspect the brakes.  This could have been a disaster.  Bob