Darryl Keirstead Posted October 6, 2020 Report Share Posted October 6, 2020 Have good brakes but they are staying pressurized, unhooked brake booster, no help. Could a defective brake light switch be holding fluid pressure on? Front brakes spin freely on hoist, back ones not so much. Any thoughts on my problem? Quote Link to comment Share on other sites More sharing options...
Plymouthy Adams Posted October 6, 2020 Report Share Posted October 6, 2020 check the rear flex hose for internal blockage..they collapse with age..pressure is great when brakes are applied, shoe returns springs not strong enough to overcome the resistance and fail to return fully 3 Quote Link to comment Share on other sites More sharing options...
Darryl Keirstead Posted October 6, 2020 Author Report Share Posted October 6, 2020 Thanks very much ,my rear flex look very good, however the front wheels turn freely, back not so much ? Thanks very much again Darryl Quote Link to comment Share on other sites More sharing options...
Plymouthy Adams Posted October 6, 2020 Report Share Posted October 6, 2020 how were you able to see the inside of the hose? good luck with your visual... Quote Link to comment Share on other sites More sharing options...
John Reddie Posted October 6, 2020 Report Share Posted October 6, 2020 36 minutes ago, Plymouthy Adams said: how were you able to see the inside of the hose? good luck with your visual... Welcome to the forum. Yes, the trouble occurs inside the hose where the hole is. The rubber can break down after time and restrict the return of the fluid to the master cylinder. I had this happen to my car once. Good luck to you. John R Quote Link to comment Share on other sites More sharing options...
Loren Posted October 6, 2020 Report Share Posted October 6, 2020 A de-lamination of a brake hose is caused by a pinhole in the inner liner. The liner fills with fluid and the harder you press on the pedal the harder it resists. That gives the sensation of no brakes. The brake dragging issue is caused by a mis-adjusted push rod to the Master Cylinder. I can't tell you how many I've replaced without even checking, I am embarrassed to say. It's an easy-peezy fix. Looking into the reservoir, push down on the pedal. When you release it you should see a gush of fluid coming from the second hole in the bottom. That's the relief port. If not then loosen the adjustment on the push rod until you do. That pressure has been known to persist for days, so no hurry. Of course there's a section of the shop manual showing the proper brake adjustment and stages of pedal engagement. Quote Link to comment Share on other sites More sharing options...
greg g Posted October 6, 2020 Report Share Posted October 6, 2020 (edited) The usual culprit is rust or debris in the relief port in the Master cylinder fluid reservoir. Does this car have the mc under the floor? Do the brake lights stay on? Edited October 6, 2020 by greg g Quote Link to comment Share on other sites More sharing options...
Plymouthy Adams Posted October 6, 2020 Report Share Posted October 6, 2020 please read the fact the man states in no uncertain terms that the front wheels turn freely while the rear stay locked....rod length and vent port blockage does not apply here... 1 Quote Link to comment Share on other sites More sharing options...
Loren Posted October 6, 2020 Report Share Posted October 6, 2020 52 minutes ago, Plymouthy Adams said: please read the fact the man states in no uncertain terms that the front wheels turn freely while the rear stay locked....rod length and vent port blockage does not apply here... My bad I didn't read fine print only the headline. However, I stand by my statements on brake hoses (which as you point out can work both directions, although I've only seen the pressure side) and push rod adjustment. To isolate the issue, while the car is on the lift, open one of the bleeders. If the rear wheels turn you'll know. I'd then remove the rear hose and have a close look at it. As I recall on this car there are other hoses between the master cylinder and the rear brakes, anyone of them can be the cause using the same logic. I am not too familiar with remote boosters but that's the next place I'd look. Quote Link to comment Share on other sites More sharing options...
Plymouthy Adams Posted October 6, 2020 Report Share Posted October 6, 2020 no problem Loren....I have been guilty a number of times of reading over a key word when replying....could just about point this ugly finger at everyone here one time or another... Quote Link to comment Share on other sites More sharing options...
knuckleharley Posted October 6, 2020 Report Share Posted October 6, 2020 8 hours ago, Darryl Keirstead said: Have good brakes but they are staying pressurized, unhooked brake booster, no help. Could a defective brake light switch be holding fluid pressure on? Front brakes spin freely on hoist, back ones not so much. Any thoughts on my problem? I know this sounds too simple,but I am a simple guy. Have you tried to back off on the brake shoe adjuster a time or two and see if this clears the problem up? I could very easily be wrong,but this problem COULD come from the brake shoes being adjusted too tightly,and then when the hubs,backing plates,etc get hot from driving,the gap tightens causing the rear brakes to drag. Quote Link to comment Share on other sites More sharing options...
squirebill Posted October 6, 2020 Report Share Posted October 6, 2020 OEM Brake light switch is hydraulically actuated but is a separate port than the ports going to the brakes. A faulty brake light switch would affect the brake lights but not the brakes unless it is leaking externally. These vehicles have 3 brake hoses, one to each of the front wheels and one between the frame and the rear axle. I dissected a front hose that was not relieving brake pressure. Ended up being rust within the crimped fitting on one end of the hose. Rust formed on the ID of the crimped fitting and squeezed the rubber hose within it to pretty much closed. Allowed high brake pressure to go in but return spring brake pressure was very slow to come out. As Plymouthy Adams recommend, check the rear hose. Run a thin wire through it to make sure it is clear. Quote Link to comment Share on other sites More sharing options...
Plymouthy Adams Posted October 6, 2020 Report Share Posted October 6, 2020 IF you do run a wire through it, round the end, make sure it is very much smooth ball so as not to abrade the inner lining....this swelling condition and or rust should truly be addressed now with a new hose if found to be distorted or dirty within as found by rodding...pay me now or pay me later type stuff where late night, shops and stores will not afford replacements and quick fixes. Quote Link to comment Share on other sites More sharing options...
knuckleharley Posted October 6, 2020 Report Share Posted October 6, 2020 55 minutes ago, Plymouthy Adams said: IF you do run a wire through it, round the end, make sure it is very much smooth ball so as not to abrade the inner lining....this swelling condition and or rust should truly be addressed now with a new hose if found to be distorted or dirty within as found by rodding...pay me now or pay me later type stuff where late night, shops and stores will not afford replacements and quick fixes. Truth to tell,the rear brake hoses ain't all that expensive,and if I am going to take one off that is of an unknown age or reliability,I'm just going to toss it in the trash can and replace it with a new one and be done with that as a potential problem. I might run a rod through the hose or dissect it later out of curiosity ,but it damn sure ain't going back on the car. I just ain't all that fond of bleeding brakes. 1 Quote Link to comment Share on other sites More sharing options...
Plymouthy Adams Posted October 6, 2020 Report Share Posted October 6, 2020 kinda of a basic idea in my above statement...it is false economy to patch an item in the category....but there will always be those that do this...some out of necessity to get the beast home and is considered a band aid and short term fix.....some out of being cheap whereas when it bites them in the butt...it is all on them... Quote Link to comment Share on other sites More sharing options...
Los_Control Posted October 6, 2020 Report Share Posted October 6, 2020 Rubber hoses from RockAuto are dirt cheap. Same issue is the quality is dirt cheap. But who sells a quality made? Everyone sells the same crap made in China and just serves it up to you on a different plate. I was really surprised when another member had something similar happen to them. Car sits for a week then back out of the driveway and A brake is locked. Seems it was a bad wheel cylinder, Would not be my first guess, but may be a place to start looking on your rear brakes. We were told front wheels spin, but rear do not turn so good. .... is that both rear wheels or just 1? I would like to think you have 4 wheel cylinders on the 2 rear wheels. Whats the chance you have 2 bad ones? Quote Link to comment Share on other sites More sharing options...
Plymouthy Adams Posted October 6, 2020 Report Share Posted October 6, 2020 not sure of the difference if given there is any but a good many of brake lines today are coming out of South America....these are well made looking units and I have these installed on a vehicle at this time.....major supplier did not list origin.....just price and availability Quote Link to comment Share on other sites More sharing options...
Dodgeb4ya Posted October 6, 2020 Report Share Posted October 6, 2020 (edited) Quick way to check if the rear hose is blocked and not letting the rear brakes release.......crack open a rear bleeder while trying to turn the wheel or drum...if it imediately frees up.....hydraulic restriction. If not shoes are dragging...not enough shoe to drum clearance. BUT...you need to.pull the front and rear drums to do a careful brake inspection instead of all us guessing...you could have two rear frozen rusty wheel cylinders too! Could be the hose, could be the M/cyl main line to the hose...spend the time check the whole system ..but don't touch the booster...just bleed it if you have to. So....When is the last time the brakes have been checked over front and rear? How long have.you owned the car...how many miles.have you put on it? These are questions we all probably would like to know to help you more accurately? Edited October 6, 2020 by Dodgeb4ya 5 Quote Link to comment Share on other sites More sharing options...
Los_Control Posted October 6, 2020 Report Share Posted October 6, 2020 9 minutes ago, Dodgeb4ya said: Quick way to check if the rear hose is blocked and not letting the rear brakes release.......crack open a rear bleeder while trying to turn the wheel or drum...if it imediately frees up.....hydraulic restriction. If not shoes are dragging...not enough shoe to drum clearance. My thinking was if it was possibly a bad wheel cylinder ... just poor machining and piston not returning. Is it possible 1 cylinder would affect both sides? I can picture a scenario where this may happen. Just throwing the idea out there because I am not sure. Quote Link to comment Share on other sites More sharing options...
Dodgeb4ya Posted October 6, 2020 Report Share Posted October 6, 2020 One frozen cylinder should not affect the other side (cause it to hang up and drag). So...Opening the bleeder screw on one side of the rear brakes will quickly and imediately let both the rear wheels turn. The above statement is true if.... *The rear hose and or main brake line feeding the rear hose is plugged... *Both rear brakes are not adjusted too tight *The wheel cylinders are operating freely.. and not corroded *Both steel lines feeding both driver's and passenger side rear wheel cylinders are open and not plugged... *The brass distribution "T" block is also open.. 1 Quote Link to comment Share on other sites More sharing options...
Dodgeb4ya Posted October 6, 2020 Report Share Posted October 6, 2020 (edited) A plugged brake hose off a 57 DeSoto brake job I did several years ago....blocked inside the crimped end...wire would not go through it. Edited October 7, 2020 by Dodgeb4ya Quote Link to comment Share on other sites More sharing options...
westaus29 Posted October 7, 2020 Report Share Posted October 7, 2020 I got a set of three usa made hoses for my 38 from Brake Hoses Unlimited, excellent price and service and included retainer clips and copper washers 2 Quote Link to comment Share on other sites More sharing options...
1951plymouth Posted October 20, 2020 Report Share Posted October 20, 2020 (edited) There is a YouTube video from the factory dated 1954 that troubleshoots the Kelsey Hayes vacuum booster. Key words to search are "master tech 1954 power brakes". Very informative . Hopefully u document on here the resolution. Thx and good luck Edited October 20, 2020 by 1951plymouth 1 Quote Link to comment Share on other sites More sharing options...
knuckleharley Posted October 20, 2020 Report Share Posted October 20, 2020 On 10/6/2020 at 8:25 PM, westaus29 said: I got a set of three usa made hoses for my 38 from Brake Hoses Unlimited, excellent price and service and included retainer clips and copper washers BTW,you can get hoses custom-made for your application locally anywhere in the nation. I've had several made up by a local BIG farmer that does hydraulic and air-conditioner repairs when he isn't farming. Don't remember what the price was on any of them,but I do remember I never had to "grunt" when paying the bill. We need to support these people whenever we can by giving them our business. Works for them,works for us. Quote Link to comment Share on other sites More sharing options...
Dodgeb4ya Posted October 20, 2020 Report Share Posted October 20, 2020 Here in the Seattle area I have tried a couple times to gave a special sized brake hose custom made for a MoPar Brake Autostop. No one would do any "DOT" brake hose work. Liability iissue. That was 30 years ago. Never bothered to try again.☹ Quote Link to comment Share on other sites More sharing options...
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