Factory Brake Job

[Don Coatney]

Good idea but what is MOT?

TOM spelled backwards

[Jeff Balazs]

MOT is their national equivalent of the DMV. They have pretty stringent road worthiness and pollution requirements and all must pass to get tags. It is actually a well thought out system as the standards are the same across the whole country. From what I understand it does a pretty good job keeping unsafe autos off the road.

 

On another episode they bought a Cobra replica that was not able to be licensed because it would not pass MOT pollution standards. The mechanic re-jetted the carb and got it 50% closer to passing just by doing this. Then they bought and installed a specially fabricated exhaust system that got them the rest of the way to passing. It's design actually got the engine to breath better too so the power was up as well. Very trick cutting edge stuff. In the end their buyer got a car that ran extremely well and it was much easier on the environment. A Win - Win result if you ask me. I am sure you can tell I really like this show. Of all of the shows out there this one seems to me to do the best job of telling things as they really are.... and properly dealing with each fault.

 

Jeff

[TheMoose]

Good idea but what is MOT?

MOT = Ministry Of Transportation.

Edited March 23, 2014 by TheMoose

[HanksB3B]

It's been a while since I posted. Well, it didn't turn out as planned the other day to be driving my truck. After rebuilding the front brakes (new shoes sized to the new drums) and then discovering that a  saturated left rear brake was the problem. I decided to rebuild the whole rear brake assembly to a new level based on tips and tricks gathered along the way.

 

For starters yesterday I bead blasted the two (as far as I know) original front cylinders and four original (as far as I know) front wheel cylinders and then again (for a total of eight) 4 of the front cylinders I've heard called "Chinese Junk" from Roberts.

 

Well in case you ever wanted to know here's the difference: The 33 year old OEM rear brake cylinder at the bottom and the newer design from Roberts. (an additional metal piston is shown to the right of each complete assembly to show the difference between the socket of the Roberts and a taperd cone of the OEM. 

 

The bead blast work turned out real well according to various local auto parts and brake repair shops. After the bead blasting , the cylinder walls were scrubbed clean with fine Scotchbrite (the method was recommended by George Shaver the master machinist at Shaver Specialties, Torrance California). I doubted the method at first but eveyone that has seen and felt the smooth finish seemed impressed and said all were rebuildable.

 

I'm also working on a power bleeding unit,  It's the same one Vintage Power Unit sells only I bought it for my BMW and am in the process of adapting a brass master cylinder plug to facilitate flushing my brake lines under pressure.

 

I believe the only reason my "yard brake job" (done at a location away from home while my truck was undergoing the frame up restore) did not hold up was the cleanliness of the hydraulic lines and possible exposure to the elements.   

 

 Dirty Brake fluid will definately shorten the life of even the best of brake jobs.

 

The body of the OEM unit weighs:                                   The body of the Roberts unit weighs: 

The OEM unit fully assembled weighs:                             The Roberts unit fully assembled weighs:   (forthcoming info)

 

The body of both feel the same in quality and weight. The main difference is in the Roberts cylinder the rubber boot is an integral part of the piston  

 

It's unfair to say they are junk and all things being equal they should last about as long. I'm from California, but It really is more Ronald Regan and NAFTA's fault than Gary Roberts. More like Raybestos chose to outsource production. 

 

To be continued...

 

Hank 

Edited March 27, 2014 by HanksB3B

[Dodgeb4ya]

I have not seen a modern day new replacement cylinders from china with a integral piston and cup.The lower picture (piston and separate cup) is typical of common new replacement new wheel cylinders.

The upper picture with the red integral piston and cup is typical of  factory Mopar  design from what I have seen as originally installed on 1946-52 Mopar cars and light duty trucks..

Piston to wheel cylinder bore is sometimes up to .010".. on new import wheel cylinders. Way too much clearance. Should be .003" max new.

Bob

[HanksB3B]

Getting ready to do what I should have done in the first place. Power Flush the lines prior to install of rebuilt cylinders. 

 

Every professional mechanic or autoparts person said they look good and the hydraulic surfaces are smooth . As far as I know these are the OEM rear wheelcylinders or the trucks 2nd?, 3rd?, most likely Raybestos cores

 

During assembly measurements were taken to match by piston and bore. Seemed to work out and assembly went smoothly.

 

Basically, the cylinders are assembled in full depth of brake fluid. 

 

The most encouraging thing was when I was done rebuilding all four cylinders, the brake fluid showed zero contamination. 

 

Tomorrow should be fun,

 

Hank 

Edited March 29, 2014 by HanksB3B

[TodFitch]

That looks like a standard quick disconnect for air tools on your pressure bleeder.

 

Is it? Is that what came on your unit? Which side has the open fitting and which the one that closes when disconnected?

[HanksB3B]

Harbor Freight Quick Dissconnect $3.99, Brass Plug Ace Hardware $2.99 but then there's Scott..

 

 

I called my friend Scott from outside his place of business. He told me he was real busy. I asked him if he could just take a look. He said o.k. When he saw the part he said "Gimme-that" and in no kidding 5 minutes Scott drilled and tapped the brass plug and I was out the door.

 

Originally, the Power Bleeder was purchased for my BMW and came only one correct plastic cap for that application. The plug for our master cylinder is a standard plumbing fitting. The master cylinder lid has to have the lid and fill plug toward therear to allow for more clearance beneath the steering column.

 

To start, I clipped a spare fitting into the quick disconnect allowing the brake fluid to flow and expel any air. Next, the quick disconnect was attached to the master cylinder. The power bleeder kept the line filled with clean, clear, no bubble brake fluid.

 

The lid to our MC is a little on the light side and even with a new gasket there was some seepage. I maintained the system at about 5 lbs of pressure. Three brake lines were closed off with plugs leaving only one line open at a time, which drained into a tube and spill cup.

 

Pressure bleeding allowed every component and connection to be checked for leakage. I seated the bleed screws but did not tighten them all the way and they appeared to be to only place the system was leaking. I'm not happy with the amount of clearance allowed at the backing plate and could not get a wrench to fit so the simple solution would be to get longer bleed screws or worst case scenario, enlarge the bleeder screw holes in the backing plate so that I  can can get a line wrench to properly bleed the brakes. 

 

No contaminated fluid remained in the lines, no fluid passed into the boots. Lots of entrapped air bubbles were removed from the system .

 

Getting closer, but still not driving,

 

Hank   

Edited March 30, 2014 by HanksB3B

[Jeff Balazs]

Somebody please explain to me the need to use a device like this to bleed these brakes?

It would seem to me that bleeding this particular system should always be possible using just the M/C and the bleeders. That is of course assuming that all the components are working correctly.

 

Is there something in the design of the original braking system on these trucks that makes it hard to bleed the system? And why would the bleeders need to be modified? I mean can't you just monitor the level of the fluid in the M/C and go about bleeding the system as it is? Am I missing something here? I know I put an entirely new disc based braking system in my truck and with a helper the bleeding process only took a few minutes. We didn't have to use any special equipment.

 

Jeff

[Merle Coggins]

Conventional bleeding requires two people. Pressure bleeding can be done with one. Also, the pressure bleeder maintains a low pressure in the system and keeps the M/C full as you purge the air out of the system. It makes the bleeding job quite easy. I used our shop's pressure bleeder on my truck when I did the brakes. It had an adapter that fit the M/C cover. It is a bladder type, like this but without the fancy wheels and pole.

 

I am in the process of making one like Hank's from a 1 gallon garden sprayer. I plan to use it to flush the brake system in my Gold Wing. It is a much more complex system with Linked brakes and ABS. I don't want to use our shop unit because I need DOT 4 fluid for the bike and we have DOT 3 in the shop bleeder.

[Don Coatney]

Somebody please explain to me the need to use a device like this to bleed these brakes?

 

 

Jeff

As Merle said. Only takes one person. My wife is not very trainable as a pedal pusher. She does not understand what is going on. Every time the pedal goes all the way to the floor she does not understand when I tell her to hold it to the floor until I close the valve. The power bleeder makes it much easier to do by myself.

[Jeff Balazs]

Ok......that is what I thought. Only necessary when you can't find a reliable helper.

I was beginning to think there was some inherent flaw in the way the original braking system was constructed.......but I couldn't for the life of me figure out what it could be.

 

I certainly can see the potential need for something like this on a very complicated modern braking system. Especially when you take into account the way offering all the latest technological advances has taken precedent over providing ease of serviceability.

 

Jeff

[TodFitch]

Somebody please explain to me the need to use a device like this to bleed these brakes?

Ditto what Merle and Don wrote: I can bleed them myself in a very short period of time. No need to train a helper, no need to stop and check the fluid level in the master. Slowest part is putting the bleed hose adaptor on (the modern style without the screw on hose adaptor came out a year or so after my car was built) on each cylinder.

[deathbound]

I know these pressure bleeders make it a 1 person job, but I could get my 9 y.o. son to do it which involves him & gets him interested in cars......."so easy, a caveman could do it". It isn't rocket science to pump, hold, release....takes about 10-15 minutes max.

Edited March 30, 2014 by deathbound

[RodFru2u]

Hey Jeff,  Not to step on Hank's toes and post but power bleeding the brake system this way had two purposes. One as the group said to bleed the brakes without a helper, (and this is a BIGGIE in Hanks situation ) to BLOW OUT the crud that might have been in his brake lines that fouled his wheel cylinders. I was there with Hank when we saw the dirt and dirty brake fluid on the rears. Not sure where all it came from but this way he is sure the line are clear and clean. I have a friend  who changes the brake fluid  ( Dot 3) in all his cars once a year, Swears by his fluid flusher. His fleet includes a couple of Rolls Royces, Bentley's and Austin Healey's . Claims that is the reason he never finds water or crud in his brake system. I don't do mine mine that often but never a bad idea if ya have the time and equipment to do so.

[Jeff Balazs]

Hey Jeff,  Not to step on Hank's toes and post but power bleeding the brake system this way had two purposes. One as the group said to bleed the brakes without a helper, (and this is a BIGGIE in Hanks situation ) to BLOW OUT the crud that might have been in his brake lines that fouled his wheel cylinders. I was there with Hank when we saw the dirt and dirty brake fluid on the rears. Not sure where all it came from but this way he is sure the line are clear and clean. I have a friend  who changes the brake fluid  ( Dot 3) in all his cars once a year, Swears by his fluid flusher. His fleet includes a couple of Rolls Royces, Bentley's and Austin Healey's . Claims that is the reason he never finds water or crud in his brake system. I don't do mine mine that often but never a bad idea if ya have the time and equipment to do so.

Interesting. I can see where this would work well flushing crud out. But I thought Hank had just made all new hard brake lines for his truck just a few months ago? Where the heck did all this crud come from? Was it the brake hoses disintegrating or maybe bad wheel cylinders? It seems to me that this problem would have surfaced when he put in all new lines..... His initial major rebuild isn't all that old either.

After reading through this thread it sure highlights some of the stuff that can go wrong on you. And I am sure we would all agree brakes are far too important to have problems like this with. Makes me really glad I went ahead and used all new components when I switched over to disc brakes.

 

Jeff

[HanksB3B]

Rod it's always nice to work with you and thanks. Guys thank for your responses I'll try to explain myself as well as I can. Merle I was actually thinking you already had a Power Bleeder made from a Farm & Fleet bug spray pump.  

 

 

It looks like there were got a lot of good answers from Merle, Don and Todd. 

 

Deathbound I'm with you when all things are good but going over my system at my own pace on my own time (not in a rush on every Saturday for two years). Looking back,  I don't like some of the work I did in a rush. I will be either replacing or rebending and re-flaring the two lines that go from the vent mounted on the differential to the upper left and upper right rear brake cylinder because I do better flares now that I've practiced some. 

 

Hank

 

Here are instructions from EIS I found in my Brake Forensic's Box:

 

 

Check out the Bleeding Procedures: 

 

 

It's easy enough to throw it all together and drive off with new brakes (at this point even though your brakes feel great). It's another thing to assemble the brakes on the backing plate and examine the complete system wheel by wheel without the drums mounted and examine every part of your workmanship with the system slightly pressurized.

 

Hank   

Edited March 30, 2014 by HanksB3B

[Jeff Balazs]

Forgive me Hank but I am trying to understand what has actually transpired with your brake system. In particular where all the "crud" in the brake fluid came from? You did just recently replace all the hard lines with new ones did you not? Were the lines that these replaced the old original lines? If so that might explain why fluid contamination was present in the system.

 

Jeff

[HanksB3B]

Forgive me Hank but I am trying to understand what has actually transpired with your brake system. In particular where all the "crud" in the brake fluid came from? You did just recently replace all the hard lines with new ones did you not? Were the lines that these replaced the old original lines? If so that might explain why fluid contamination was present in the system.

 

Jeff

 

All the lines are new but I suspect they became contaminated from cylinders that were not clinically re-built but rather rebuilt on the truck at Ricardo's yard.   The next year, the truck sat with new lines and who knows what fluid or how much rain for a year while the Body Parts were being painted.

 

Hank   

Edited March 31, 2014 by HanksB3B

[Jeff Balazs]

Now I understand. This is certainly a good example of why flushing the entire system out makes a lot of sense.

I always get a bit concerned when I read here of somebody attempting to reuse the old lines in a truck that has set for a long while.

 

Jeff

[HanksB3B]

The major benefit to using a pressure bleeder is that the lines can be flushed independently from the brake cylinders.

 

 Here the right side is plugged while the left side is being flushed. Contaminants, especially grains of dirt and rust can hide inside the cylinder body and reintroduce themselves in new fluid.

 

 

I'm glad someone mentioned the old soft copper washer used beneath the flare fitting that goes into the rear brake cylinder. A vise was used along with a line wrench and a hammer to tighten the flare fitting. I find that by using a hammer lightly, I can feel when both metal surfaces seat with a spring-tension-like torque.

 

Right now my problem is with the bleed screws Here's the reason I have now dubbed my NAPA store as NADA. Look at that beautiful completely empty plastic case  (who's minding the store) I need a source for the OEM bleeder valves.

 

and of course the one that isn't numbered is the Mopar part I need...

 

Hank     

Edited March 31, 2014 by HanksB3B

[Barry Maxwell]

Hank:

As you probably know, the NAPA numbers for the front and rear  bleeder screws are 11410 and 10591, respectively. Do you have a source or a NAPA number for the flare fitting shown in you second photo? I have been having significant trouble sealing this fitting to the cylinder surface  with a copper washer. Someone suggested annealing the washer to soften it. I tried that and it still seeps under pressure-even when I apply much torque and a rap with a hammer. I am about to try a "crush" washer in the hopes that will work. It may be, however, that I need new fittings. My NAPA stores don't have the fitting.

Barry

 

P.S. I am using speed bleeders on the front brakes and they work well. The NAPA speed bleeders for the rears are the wrong size. Thus I am using the 10591 screws. 

[P15-D24]

Hank:

As you probably know, the NAPA numbers for the front and rear  bleeder screws are 11410 and 10591, respectively. Do you have a source or a NAPA number for the flare fitting shown in you second photo? I have been having significant trouble sealing this fitting to the cylinder surface  with a copper washer. Someone suggested annealing the washer to soften it. I tried that and it still seeps under pressure-even when I apply much torque and a rap with a hammer. I am about to try a "crush" washer in the hopes that will work. It may be, however, that I need new fittings. My NAPA stores don't have the fitting.

Barry

 

P.S. I am using speed bleeders on the front brakes and they work well. The NAPA speed bleeders for the rears are the wrong size. Thus I am using the 10591 screws. 

 

Again, these should be SAE 45 degree double flares.  Never use any washer/o-ring on a double flare! The washers are for use on banjo fittings! 

[Barry Maxwell]

P15-D24:

The fitting I am talking about is shown in Hank's second photo (post 121) and is shown in my Parts Manual as a "Connector" (5-66-1) together with a "Gasket" (5-62-7), aka Washer. The fitting has machine threads and screws into the upper wheel cylinder and accepts the double flare brake line from the T-block mounted on the rear axle. I hope this adequately describes what I am talking about. BTW, my project truck is a '51B3C.

Barry

[P15-D24]

P15-D24:

The fitting I am talking about is shown in Hank's second photo (post 121) and is shown in my Parts Manual as a "Connector" (5-66-1) together with a "Gasket" (5-62-7), aka Washer. The fitting has machine threads and screws into the upper wheel cylinder and accepts the double flare brake line from the T-block mounted on the rear axle. I hope this adequately describes what I am talking about. BTW, my project truck is a '51B3C.

Barry

5-66-1 is only used on 1 ton and larger trucks which use a banjo bolt to hold the connector in place. It is not used on B or C series trucks. See page 5-15 of the part book, note the connector is only used in the illustration for 3-4 ton trucks. I have seen two types used on the B & C series trucks: one where a SAE 45 degree fitting is machined into the wheel cylinder or a pipe thread is machined in and you screw in a brass or bronze fitting with pipe thread on one end and a female SAE 45 on the other end to accept the brake line SAE male fitting.