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1969 Fleetwood, Brake Issues

Started by WTL, September 07, 2016, 06:40:31 PM

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WTL

My brakes have gone from bad to worse, and the service manual really isn't helping. 

About a month ago, I realized that the front MC reservoir had gone dry so I filled it back up.  I don't think it was dry for long, and discovered that after seeing a good bit of fluid seepage around the cover. 

The brakes have degraded over this time, and now I have a set of symptoms that I dont understand. 

First, the pedal got very low, the application of the brakes felt smooth but with little stopping power so I went to bleed them. 

The rear drums however just will not bleed, almost no fluid at all. What fluid that was in the system did have rust and was ugly.  I tried gravity feeding even and might have had a shotglass worth of fluid come out of both side over the course of an hour.  Also tried a mittyvac hand pump, and the speed bleeders to no avail. 

I then went to try and bleed the fronts, and while there was some fluid there and I think I bled them but now they are not disengaging.  The pads drag when I drive.  When I stop, it is weak, with pretty low pedal, and the car nose dives which I guess is because I have no rear brakes. 

I am tempted to think all of this might be related, and that either I have a master cylinder screwing everything up, or some sort of proportional valve, metering valve or other 1969 specific thing causing the fluid to not do right...the shop manual just says there is a distribution block behind the drivers wheel well, and a metering valve...are those my problem?  I've heard of later combination valves possibly shutting off all fluid to the rear drums, but nothing about that being a feature specific to this car.    Should I start with replacing the master cylinder and front calipers and pretty old rubber brake lines in front? 


Scot Minesinger

I own 1970 Cadillacs which enjoy a similar system. 

What is the history of the brake system?  I bought a 1970 SDV with 35k miles on in it in 2012 and the brake light was on and braking was poor.  I replaced everything, pistons, calipers, shoes, pads, master cylinder, booster, three rubber flex lines, and even the metal brake lines.  Then the system worked great.

This is a critical system as you know.  Anything that has not been recently replaced probably needs to be.  The original steel lines rust from inside out (and from outside in), as brake fluid draws in moisture.  If you can't bleed rear brakes, the steel lines probably need to be replaced.  Brake fluid loss and drips on floor could be anything (piston, caliper, rubber line failure, rust thru of steel lines).  You are likely in for the same thing as me.  It took a weekend and the parts as breaks go was reasonable (under $500 I think).  If you fix one thing and leave older components you may be in for a let down later.
Fairfax Station, VA  22039 (Washington DC Sub)
1970 Cadillac DeVille Convertible
1970 Cadillac Sedan DeVille
1970 four door Convertible w/Cadillac Warranty

WTL

I'm thinking that a lot of the lines are original, although there was a pretty extensive going through of the car in 89..thats ages ago now, too, even if they did get into the brakes. 

I tend to want to do as you did and replace everything, but it seems that OPGI doesn't carry steel lines for a fleetwood, only the Devilles and smaller.  Did you have your lines made, or is there another supplier I might try?

Also, that leaves the distribution block and metering valve...did you replace those and if so where did you get replacements? 


Jeff Rosansky CLC #28373

I had the same thing with my rear brakes when I got the car. So much so that I took the bleeders off because I thought they had to have been plugged. I ended up taking a clear tube and put it on the nipple. Then I just sucked until crap came out. And I mean crap. Flushed and flushed until got clear fluid.
As for the fronts, if they both don't release it has to be something common to both. Check the rubber lines. They can collapse from the inside out. It could collapse and hold pressure. As the fronts are on the same line, pressure in 1 side means pressure in the other. Next time they drag, Crack open one of the rubber lines. I bet fluid will squirt (not dribble) out.
Be sure to use multiple wrenches when working on the lines. Sometimes those fittings seem to weld together and you don't want to brake (ok, pun and spelling intended) anything.
Jeff
Jeff Rosansky
CLC #28373
1970 Coupe DeVille (Big Red)
1955 Series 62 (Baby Blue)
Dad's new 1979 Coupe DeVille

savemy67

Hello WTL,

From your post, it is likely that air entered your MC when it ran dry.  Air is compressible so that may account for the pedal feel but lack of stopping power.  Since brake fluid attracts moisture, it is also likely that moisture entered your MC.  Moisture will corrode the steel lines and iron in the MC, calipers, and wheel cylinders.  Since you found your MC dry, it may have been leaking for some time, and since you said the brakes have not been serviced since 1989, you are lucky that you have not had a major brake failure resulting in a serious accident.  I once drove a Chevrolet 10 miles without any fluid in the MC, but I never exceeded 10 mph.  If you are driving your 2 1/2 ton Fleetwood at 60 mph, thinking that you might have a brake issue, you will sooner or later have an issue much greater than a bad MC.  I am not an alarmist, but at 60 mph, a car travels 88 feet per second.

The symptoms you describe sound like your entire brake system is in need of repair - MC, lines, hoses, wheel cylinders, calipers, distribution blocks, and proportioning valve.  Based on your post, I don't think you can replace any one component and have a reliable system on your car.  If you can do the work yourself, you will save a bundle.  If you have a shop do the work, you will spend a bundle.  On the positive side, the brake system on your '69 is not that much different than brake systems on today's cars, minus the ABS.  On the negative side, you need to find a shop that can do a good job.  This might be difficult based on where you live.

If you purchase the parts yourself, many of the parts should be available at places like RockAuto.  You don't have to go to a vintage Cadillac supplier to get most brake parts for your car.  If you think you can do the work yourself, you can buy the brake line tubing, fittings, a double lap flaring tool, and a tubing bender, and make your own lines using the old lines as templates.  Good luck, and be safe, for your sake and others'.

Respectfully submitted
Christopher Winter
Christopher Winter
1967 Sedan DeVille hardtop

Scot Minesinger

OPG has been not positive for me to say the least (and I'm really restraining myself - don't buy from them).  Bought my parts from USA Parts in WV 304-724-6600 with great results.  The steel lines would be same for Fleetwood except front to rear is maybe 3 inches too short.  You will have to likely cut the front to rear anyway to puzzle it in unless you have body off frame.  You can add a three inch extension with double flare fittings.

In-line Tube I think makes the brake lines.  Stainless steel lines can be difficult to seal, so I would stay with conventional steel.  The conventional steel lines also include an alloy liner so they will not rust, plus they bend a little easier than the stainless lines.

You could really go thru the existing system (spending considerable time) and find 50% of it salvageable, however I think it will be way better to replace it all.  The added cost of parts to replace it all will be offset in diagnoses time.

I re-used the two brass blocks anchored to frame on driver side, but cleaned them up.
Fairfax Station, VA  22039 (Washington DC Sub)
1970 Cadillac DeVille Convertible
1970 Cadillac Sedan DeVille
1970 four door Convertible w/Cadillac Warranty

Bobby B

#6
Scot,
I think Classic Tube has the Fleetwood Limousine brake line set. Would that set be of any help? I always make my own lines after I pull the originals off and duplicate them with various benders and the Hydraulic flare tool. Piece of cake, but it's probably cheaper to buy them pre-bent, but I enjoy doing it.
                                            Bobby

http://www.classictube.com/catalogsearch/advanced/result/?name=&description=&short_description=&sku=&price%5Bfrom%5D=&price%5Bto%5D=&year=1969&make=Cadillac&v_model=Fleetwood%20Limousine&cab=&ton=&duty=&drive=&box=&engine=&ymm_cat=Brake%20Line%20Kit
1947 Cadillac Series 62 Convertible Coupe
1968 Mustang Convertible
1973 Mustang Convertible
1969 Jaguar E-Type Roadster
1971 Datsun 240Z
1979 H-D FLH

WTL

OK, I'm ordering the supplies for the big job.  Gonna replace lines, MC, Calipers, all pads, wheel cylinders and go from there.  Right now I'm not ordering drums or a kit for the rears, but I'm gonna take then off the car and get a good look.  Yall basically gave me the cover to justify replacing whole swaths of the system instead of trying to flush and target the fix.  I still don't know about the distributing block or metering valve, I am just gonna see if I can clean it out when I get it off and go from there.  I'm not aiming for period authenticity, but like Chris Winter noted, stopping the car is no small thing.  Thanks for the help folks, I'll let you know when she is back on the road. 

savemy67

Hello WTL,

I believe the distribution block is a passive device.  It is no more than a junction in the hydraulic system plumbing, similar to a T in a water line.  The proportioning valve is an active device.  Since the majority of breaking force is accomplished by the front wheels, the proportioning valve ensures that the rear brakes apply without them locking up, thereby avoiding a skid.  If your junction blocks can be cleaned thoroughly, they can be reused.  This may or may not be the case with your proportioning valve.

The wheel cylinders and calipers can be rebuilt for a fraction of the cost of replacing them if they are in good shape (no pitting in the bores), although this is a relative valuation, not an absolute valuation.  Be sure to obtain a '69 shop manual, read up on hydraulic brake systems, take your time, be careful and clean, and you should have success.

Christopher Winter
Christopher Winter
1967 Sedan DeVille hardtop

WTL

Follow up time -

I'm about 80 percent of the way through replacing what I was gonna replace, so, master cylinder, front calipers and pads, and I've done the front hard lines. 

I havent tested everything yet, but I think a significant problem was deteriorated rubber lines.  One of the front ones was delaminating on the outside, I can only imagine the inside.  The other one when I cut it seemed to be badly narrowed, cruddy, hard to imagine much pressure seeping through. 

I should of, but I guess I didn't realize there was a rubber line on the rear...so I didnt order one from rock auto.  After still not getting any fluid to the rear drums even with the new MC, I crawled back under and discovered it.  Took that off, and the hard line dripped fluid for a while...assumption is the steel lines are ok, and that last rubber line was a big problem. 

My working theory is as long as everything in the system was wet, the rusty nasty fluid was able to move and work to some degree...but once I let the MC run dry that one time, it hardened the rusty fluid into a clayish type gunk.  I have high hopes on slapping the new hose on tomorrow that I will have better brakes than I have ever seen on the car. 

Thanks all for the help, I will be back once its done. 

savemy67

Hello WTL,

If you have access to compressed air, blow out the steel lines aft of the front steel lines you replaced.  You would not want to push any gunk in the lines through the rear wheel cylinders.

If you do not have access to compressed air, buy a gallon of brake fluid, and leave the rear wheel cylinders disconnected, and pump some fluid through the lines/hose to clean out any gunk before connecting the rear wheel cylinders.

Respectfully submitted,
Christopher Winter
Christopher Winter
1967 Sedan DeVille hardtop

WTL

Thanks for your help Christopher, I did that, reattached the hose, and am happy to report that my brakes are back and better than I have ever had them on the car.  Very smooth, good stopping power, and the feel is right...I'd say these 60s disk/drum brakes are really surprisingly decent, very similar to what my 1995 ram has in stopping power.