55.2-59 Brake issues

[2bo.c10]

Hi Everyone -

Background: I installed a new master cylinder about a month ago and attempted to bleed the brakes immediately after installing it.
Back right: Bled Great!
Back left: Bleeder is screw was stripped
Front right: Bled when it was first cracked open, but then that was it! Every time I would try to bleed them after that nothing would come out.
Front left: Bled fine, but the fluid seemed murky. This is weird considering it should have all new fluid running through the lines. I bled it about 5 or 6 times but kept getting the murky brake fluid.

Before doing any of this there was NO pressure in the pedal and after doing the above I had great pressure in the pedal. I have drum brakes all around.

Moving forward...

The Issue:Yesterday I take my truck out of the garage for the first time since I bought it - Thought I could make her maiden voyage a VERY short trip (not even 1/2 mile away) to my mother's for christmas. Didnt work out that way... As I drove it up the street, when I would brake, it would seem fine (didnt pull to one side or anything like that) but as the truck would come to a stop from braking, it seemed like one of the wheels was locking up. It wouldnt happen right away when the brake was applied but as the truck was finally coming to a stop.

Based on what I've described, anyone have any idea on what it could be? Any and all help is very much appreciated!! Thank you!

[dsraven]

we will need some more info
is the brake system all completely stock? drum brakes and single system master cylinder mounted under the floor?
did the master cylinder EVER run dry on fluid when you were bleeding?
have you looked at any of the other brake components, steel lines, rubber hoses, brake shoes, park brake cables and brake adjustments?
are you sure you have a bottle of brake fluid and not something that looks like a brake fluid bottle (don't laugh or get mad, this happens. somebody mistakenly puts a "same brand" bottle of another product, that is packaged in the same color bottle as the brake fluid bottle, on the shelf where the brake fluid is placed. you grab it thinking it is brake fluid and dump it in. that is why the fluid looks murky, because when the brake fluid is mixed with this other product the outcome is murky fluid. I know a guy who filled his master cylinder with diesel fuel additive because somebody had put a bottle of the additive on the shelf where the brake fluid was. the 2 bottles looked the same and were the same color). another reason for murky fluid is water contamination. if there is water in the brake lines for some reason then that would explain it. air bubbles in the fluid can also make the fluid look murky. try to get a sample and see if the murky goes away after the sample sits long enough for the bubbles to find their way out. or keep bleeding until clear fluid comes out at each bleeder hole. start the process by cracking the lines at the master cylinder to bleed the master cylinder ports. then work your way back and bleed at each connection from there to the furthest away wheel, usually the passenger's side rear. then the drivers side rear and so forth. have a friend help you and have him press on the brakes before you crack the fitting or bleeder, then hold the pedal down until you have the bleeder or fitting tight again. then check the fluid level in the master and go to the next bleed location.
if you can't get the bleeder screws to come out then you can also simply loosen the brake line fitting on that cylinder to assist with the bleeding. you really should replace the bleeder screw or the wheel cylinder though. I have found that you spend more time trying to fix the bleeder screw than if you just replace the wheel cylinder right outta the chute.
have you checked the linkage for the brake pedal to ensure the free play is correct and also the linkage is not binding or worn out? I assume the master cylinder cap is new as well as the master cylinder? new, like from the store. not "new to you"?

[2bo.c10]

Thanks for the detailed reply- see my responses in bold

Originally Posted by dsraven

we will need some more info
is the brake system all completely stock?Yes, completely stock drum brakes and single system master cylinder mounted under the floor?yes, drum brakes and master cylinder is brand new and mounted under the floor
did the master cylinder EVER run dry on fluid when you were bleeding?No, I dont believe so - we were paying attention to the fluid inside the cylinder while we were bleeding the brakes
have you looked at any of the other brake components, steel lines, rubber hoses, brake shoes, park brake cables and brake adjustments?Honestly, no.
are you sure you have a bottle of brake fluid and not something that looks like a brake fluid bottle (don't laugh or get mad, this happens. somebody mistakenly puts a "same brand" bottle of another product, that is packaged in the same color bottle as the brake fluid bottle, on the shelf where the brake fluid is placed. you grab it thinking it is brake fluid and dump it in. that is why the fluid looks murky, because when the brake fluid is mixed with this other product the outcome is murky fluid. I know a guy who filled his master cylinder with diesel fuel additive because somebody had put a bottle of the additive on the shelf where the brake fluid was. the 2 bottles looked the same and were the same color).Yes, Im positive its brake fluid another reason for murky fluid is water contamination. if there is water in the brake lines for some reason then that would explain it. air bubbles in the fluid can also make the fluid look murky.it was murky and dirty looking. very brown try to get a sample and see if the murky goes away after the sample sits long enough for the bubbles to find their way out. or keep bleeding until clear fluid comes out at each bleeder hole. start the process by cracking the lines at the master cylinder to bleed the master cylinder ports. then work your way back and bleed at each connection from there to the furthest away wheel, usually the passenger's side rear. then the drivers side rear and so forth. have a friend help you and have him press on the brakes before you crack the fitting or bleeder, then hold the pedal down until you have the bleeder or fitting tight again. then check the fluid level in the master and go to the next bleed location. this is the exact process I went through to bleed them
if you can't get the bleeder screws to come out then you can also simply loosen the brake line fitting on that cylinder to assist with the bleeding.great idea! I hadnt thought of that! you really should replace the bleeder screw or the wheel cylinder though.I bought all new wheel cylinders but havent installed them yet. I have found that you spend more time trying to fix the bleeder screw than if you just replace the wheel cylinder right outta the chute.
have you checked the linkage for the brake pedal to ensure the free play is correct and also the linkage is not binding or worn out?Yes, I believe linkage is correct. It is correctly mounted the master cylinder I assume the master cylinder cap is new as well as the master cylinder? new, like from the store. not "new to you"?Yes, it is a brand new master cylinder as well as new cap

[nvrdone]

sounds to me like you have at least one bad wheel cylinder. id start by replacing all 4 wheel cylinders and all the rubber hosed. then I would pump all new fluid thru the system until it comes out clear at the wheel cylinders. then bleed the system

[dsraven]

before doing much driving around, if any, I suggest to do a thorough inspection of the brake system and replace those wheel cylinders since you already have new ones anyway.
-pedal linkages and pivot points are all free moving, lubricated properly and adjusted properly
-pedal return spring is in place and adequate to return pedal all the way back to it's stop when the brakes are released
-cab mounting is sufficient so as not to interfere with any brake pedal linkages. felt grommet on floor of cab is not binding with the pedal shaft
-steel brake lines and all other connection points are all in good condition and not rusted at any frame contact points, retainer clamp points etc. steel line over differential is intact and shows no signs of mechanical damage (dents, extra bends, kinks etc). T connection over the differential is in good shape and retained properly. all hoses and steel lines have the proper retainers in place to keep them from mechanical damage
-rubber brake hoses are all in good condition and do not show signs of age/cracking when bent/flexed. crimp connections on hose ends are all in good condition and no signs of leakage
-park brake linkage is all connected, free moving and operational. park brake linkage should be backed off prior to brake drum removal and any brake work, like wheel cylinders, is done. then, after the brake work is complete the brake shoes should be adjusted as normal. after that the park brake should be adjusted. it is important to do these steps to adjust the brakes properly otherwise the park brake adjustment, if not released, can affect the service brake adjustment. if the park brake is not adjusted properly after the service brake adjustment is complete then it can have an affect on brake performance. some guys will simply not have a park brake and then complain that they always need to pump up their brakes. that is because the park brake adjustment keeps the brake shoes from returning the wheel cylinder's pistons all the way back into their bores. when this happens it takes one pump of the pedal just to get the pistons out far enough to make the shoes contact the brake drums
-I will leave out the part about wheel cylinders because you have new ones to install but will add that the steel line connections are all tight and not leaking/kinked/twisted as can be the case sometimes after brake work has been done. a lot of times the steel line gets twisted because the flare nut is seized onto the steel line. if it looks suspect simply replace the line, they are pretty cheap anyway.
-brake shoe lining and drum max diameter are within serviceable limits. no lip is present inside the drums
-brake backing plates are in good condition and do not show signs of wear or grooving in the brake shoe contact areas
-brake hardware (springs, shoe hold down hardware, park brake hardware etc) is all in good condition and complete
-rear axle seals are not leaking, differential vent is serviceable and not plugged (plugged vent causes pressure build up and makes axle seals leak all over the brakes. oil on brake shoes actually makes them stick and causes the wheels to skid rather than making the brakes slippery like one would think)


if doing the wheel cylinders I would recommend disconnecting the steel line at the master cylinder and at each wheel cylinder and collecting any fluid that will drain by itself by gravity. then, before installing any new parts, get a can or 2 of brake cleaner and blow out the steel lines from the master cylinder end on down until clean fluid comes out each steel line at the wheel cylinder ends. this will keep any debris, rust or other contaminants from getting into your new wheel cylinders. if you have an air compressor you can use a rag over each steel line (this will keep the fluid from becoming airborne or aerosol'd), held on with tape or what have you, and then use low pressure air (like 5 psi) to help you clean the lines of fluid or brake cleaner. remember that brake fluid is like paint remover so be careful not to get any on the painted surfaces or your skin/eyes etc. dot 3 or dot 4 (like what would normally be used in these systems) brake fluid also likes to absorb water so never use an old can or especially an unsealed old can. I assume the murky fluid you seen is simply dirty fluid from a dirty system, those old master cylinders didn't exactly have a great sealing lid on them and the master lives down on the frame where dirt/mud/moisture can collect. that is the reason why manufacturers advise to have the brake fluid flushed yearly or at least at every brake job. this is especially important for vehicles with disc brakes, those calipers get stinkin hot and the fluid can actually turn color from the heat. dot 5 fluid is silicone based and doesn't absorb water so some guys will use that for vehicles that sit around a lot. the whole system needs to be flushed and cleaned prior to using the dot 5 fluid though
anyway,
do the inspection and get the related parts required. hoses, steel lines, fluid, hardware kits etc
spray some penetrating fluid on the holes in the brake drums where the wheel studs and axle flanges come through on the rear brakes. you can help this along a bit by tapping the brake drum between the wheels studs to set up some vibration and get the fluid penetrating the area faster. the front brakes need to have the wheel bearing hub assembly removed to access the brakes I think-it's been awhile so not totally sure on that
back off the park brake
back off the star adjuster wheels so the shoes have a chance of clearing the lip on the drums
then pull the drums, spray down the whole area with some water in a hand pump squirt bottle (you don't want to inhale any of that dust or sweep it up later and get it airborne) and see what you have
take a pic of the system set up before you disassemble so you can reference that when it is assembly time or have a manual with you to ensure you get it right
if using the old drums and shoes you can use a drum sander to cleanup the brake drum surfaces and some brake clean and course sandpaper to clean up the old shoes. remember to wear respiratory protection because brake dust is carcinogenic. an automotive machine shop or a parts store that machines brakes can probably measure the drums for free to ensure they are within the wear limits. if there is any grease or oil on the linings it is rcommended to fix the leak first then replace the linings. the material is like a sponge and it may look clean after using brake cleaner but when the brakes heat up the grease or oil will be released from the lining material and you will have the same problems right back again.
https://www.harborfreight.com/4-piec...set-35455.html
if replacing the shoes and having the drums machined remember that the new shoes will not fit the over sized drum well. some places may still sell oversized shoes-these have a thicker lining material attached to the normal shoes. they are actually meant to be arced (ground down) to fit the size of the now larger brake drum so if installed right out of the box with no re-arcing done they may be a tight fit. they will also not contact the drum like they should so they will need some attention for the first little bit until they "wear in" and fit the drum. the re-arcing process is manual at that point so they will need to be adjusted as they wear in. you will also not have great brakes until they do wear in because the whole shoe friction material surface is not contacting the drum, only a small part of it. sometimes it is a little more money to buy new drums but worth it in the end. use some brake shoe lubricant on the backing plates where the shoes contact (small amounts) and use some anti seize compound on the star adjusting wheel threads (unscrew the whole thing, clean and apply). use anti seize on the axle flange as well before installing the drum. this will help with the seized on brake drums next time.
when adjusting the brakes after assembly tighten the star wheel until the shoes are tight against the drum, then back off the star wheel 7 notches. then adjust the park brake.

maybe some info here for you

http://chevy.oldcarmanualproject.com...esto/index.htm

hope that helps somebody out there. sorry it got long winded

[nvrdone]

my guess is since its a drum brake system you may have brake shoes that are coated with grease or brake fluid. any idea which wheel is locking up? id start with a complete inspection. I would also consider replacing shoes, wheel cylinders, hoses & master cylinder. that way you eliminate any potential problem / failure in the future.

good luck

[mr48chev]

I have to agree with the idea that one of those old cylinders might be sticking and or there is brake fluid or grease on some of the brake shoes.