In process of rebuilding all brakes and have run into numerous complications. Good on lines and wheel cylinders front and back. Found front shoes, Centric 111.02990, but cannot locate a hardware kit (return springs, pins, retainers, etc). I can find 15"x6" shoes for the 17,500lb rear axles, but I cannot locate the 15"x4" shoes for my 15k lb axle. I spoke with two different NAPA's and both could find the parts, but all were listed as no longer available or not manufactured anymore.
Does anyone here have any suggestions on where to look/who to talk to? Current shoes are not "bad," but the hardware is all pretty well worn out and rusted to the point of probably not being safe and thus needing replaced. I figured that while I was at it, I might as well freshen the shoes.
Also, my master is a single piston master, but it has two lines. One from the tip of the piston reservoir that feeds to hydro vac, and another off the lower passenger side of the master. I thought this was normal until I received my replacement today and found it to only have a single line. Sometime tomorrow I will trace that second line, but until then, any idea at all what a second line would be for? Every replacement I look at is a single line unit. Second line is larger as well. Looks like 5/16.
Hy HFfarms, I found Raybestos part number H9200 that kit contains all the hardware for both your reline projects if they are Wagner manual adjusting brakes, two kits are required for each axle. I checked RockAuto and they are available for $15.60 each. I haven't checked on the 15" X 4" shoes yet but I will look around, hope that helps.
Hy again HFfarms, I thought there was something odd about how you only had a single master cylinder. Does your truck have an automatic transmission? One other thing I wanted to mention, in future posts please include the year and model designation for the truck you are inquiring about. Some detective work on your previous posts told me that at least one of your trucks is a 1964 C60, that truck would have a two chamber master cylinder if it had a standard transmission, one chamber would operate the hydraulic clutch. Please verify what you have exactly?
Ah ha! Greatly appreciate the feedback 3B. Yes the truck in question is a '64 C60. 4sp manual 292. Apologies for not including, I was more or less looking at the whole range 60-66 (barring '66 self adjusters) as according to my books, the brakes are common across the years 'per axle'. Feel free to correct me if I am wrong. All my brakes are self centering, manually adjusted, so any self adjusting from '66 is out of question.
My local NAPA got back to me late in the day Friday and indicated they may have found front hardware. I'll pick it up tomorrow and know by Tuesday if its the correct hardware. Still nothing for the rears though. Once I get the fronts back together this week I'll dismantle the rears and take measurements and inspect.
As for the Master, I'll trace that second line tomorrow. I've been ill and unable to get out to the truck otherwise I would have an answer right now. It is 100% a single piston master, and that second line is not for the clutch or anything engine/drive-line related (i didn't disconnect any hydro lines on the pull-out). I cut only two lines on the hydro-vac upon removal, so this second line is a total mystery to me. Ill know tomorrow though and report back.
Hy HFfarms, If you could provide picture of your brake assemblies with the drums removed that would be very helpful, in the mean time, do you remember if you could see a brake line crossover tube on the outside of the rear brake backing plates?
Alright here we go. First off, the hardware kit Napa found was part number 2314 and was not correct. Springs were too long and the Maxi-pack didn't have the pins or other associated hardware. Back to square one. I will run the H9200 part number to ground for comparison.
Attached you will find a photo of the front hardware in question for the 5k lb axle. I apologize as I have no photo of it assembled, I got overzealous and didn't take photos on disassembly. I do not yet have the rear wheels/drums off as I am waiting to get the fronts back together. Call it a bad setup that requires two corners be grounded at all times and chocked in pace.
Secondly I traced the line. Surprisingly, its a second line to the hydro-vac. Refer to the photos attached. It is a larger 5/16" line that juts out the side of the master reservoir, then runs adjacent to the primary 1/4" line back to the hydro-vac. In the photos, the red is that second, larger line and the blue is the primary, smaller line. The blue connects into the back of the hydro-vac by the diaphragm, and then pops out the top of the hydro-vac at the end of the piston and immediately connects into the frame where it T's off to fronts and rears. The larger 5/16" line leaves the tip of the hydro-vac piston and doubles back to the master. Im assuming its a high pressure return line? Also none of this follows my books, so I am assuming the setup is not factory?
Due to this, I either need to return the new master I have for a single piston with a second outlet model, or keep it and replace the hydro-vac with an appropriate unit that is only a 2 line unit. Any advice? Hydro-vac is at minimum getting rebuilt.
*EDIT* Additionally, the hydro-vac is not factory original. It has a "reman" sticker on it so this is a later life replacement. Im wondering if previous owner overhauled the system at the time of replacement to a different hydro-vac and opted for the additional line and different master. Again, no master I have yet seen that is factory for these trucks runs this two outlet setup.
Another point of contention: before being ripped apart, this sucker stopped, and I mean STOPPED on a dime (or rather skidded). It took an extremely feather foot on the brakes to not lock them up, even after adjusting the pedal for travel. I chocked it up to rolling around empty, but I now wonder if the system was upgraded for better stopping power under load.
*EDIT* *EDIT* Hydro-vac is a rebuilt unit of the "Prior Rebuilder" company out of Garland TX. Tag reads: 22BBM 2501850 Digging into that now to determine application of this specif hydro-vac unit.
I don't know what is going on with the hydraulic lines as far as their function, never seen anything like it. The installation along the frame looks original to me with all the clamps and well formed tubing.
The springs and other hardware look like very standard stuff, even to perhaps being the same as light truck parts. None of those parts are really critical for dimensions, I would be inclined to talk my local parts counter man into bringing out several kits and look through them for the parts that match. It might be necessary to buy a couple kits to get everything. The other route would be to do directly to somewhere like Brake and Equipment Warehouse in Minneapolis, https://brakeandequipment.com/
Mac :{)
1962 K10 short step side, much modified for rally 1969 T50 fire truck, almost nos, needs a few things
Hy HFfarms, your master cylinder should be Napa p/n NMC M34403, the hardware kit could be Napa UP2474 but I could only find a listing up to the 50 series. Just to clarify you have 14" X 2.25 front brakes with two single acting wheel cylinders, correct?
Alright I think I answered myself here. Unit numbers match for the truck series. The confusion comes from the understanding that the 11" diaphragm unit does not match this. This truck has the optional brake package, the 12.75" diaphragm booster style which has a third lead at the tip of the unit that feeds back to the master, "the function of which is to compensate for for any loss of fluid from the Multi-Vac hydraulic cylinder."
In layman's terms, a high pressure return line. This hydro-vac was a factory available upgrade as per my book in front of me. So, now to locate the corresponding master cylinder part number to work with this unit. Apologies for overlooking a page in my manuals and missing this.
Hy HFfarms, your master cylinder should be Napa p/n NMC M34403, the hardware kit could be Napa UP2474 but I could only find a listing up to the 50 series. Just to clarify you have 14" X 2.25 front brakes with two single acting wheel cylinders, correct?
Lord almighty I owe you a beer good sir. Yes fronts are a single wheel cylinder setup and 14" x 2.5"
The MC part number you have is the same as the one here on my front table, and it is only a 1 port master.
Hy HFfarms, I am with sweepleader, as I have never encountered the line setup you have on your master cylinder. As you showed in your pictures the apply line from the master enters the booster close to the diaphragm, the booster output line is at the end of the cylindrical projection at the end of the booster, the output line is usually a single line leading to a tee on the frame which leads to the front and rear brakes on a single chamber system. By adding the second line from the booster output back to the master cylinder you are sending boosted pressure fluid back to the master cylinder and making a big loop with some apply fluid and some boosted apply fluid. If it were my truck I would remove the second line back to the master cylinder and plug the second outlet on the booster output, and see how the brakes function, hope that helps.
If you are going to keep the two line MC and can't find a replacement...just send it out and have it sleeved and a new kit installed.
I wonder if the return line is like a quick release, when the brake are released after a stop, it returns the fluid back to the reservoir fast...just a guess.
If it were my truck I would remove the second line back to the master cylinder and plug the second outlet on the booster output, and see how the brakes function, hope that helps.
If I am unable to locate part numbers for the master, it very well could be the only option. Any idea if these master's have a part or serial number stamped on it anywhere? I am yet to find any solid info on the operational difference between the 11" and 12.75" hydro-vac systems. I wont lie, I like the idea of more brakes, its never a bad thing especially as this girl will load heavy.
Originally Posted by Mike B
If you are going to keep the two line MC and can't find a replacement...just send it out and have it sleeved and a new kit installed.
I am looking into this possibility currently.
If you refer to the original image, you can see the discoloration and rust in the master area of the firewall. Whatever seal used to be on the master cap is long since gone, and that return line puts some serious pressure back into the master clearly as it shoots it everywhere on the firewall as well without that seal. This was the main reason for replacement.
To be clear, both the master and hydro-vac still function fine, but the significant corrosion means limited life. With the engine out I figured its best to refresh everything as I have to do the brake lines regardless. Ill work with Napa again tomorrow on these items and report back with what I find.
Somewhat related topic, is there a master list parts book for these trucks somewhere? None of the factory manuals carry part numbers, and its killing the efficiency of finding parts and cross referencing part numbers. Just curious. Id buy it in a heartbeat.
Hy HFfarms, yes there are parts books they usually cover a range of years and are usually split into light trucks, medium duty trucks and heavy duty trucks. They can be a mystery until you learn how to read them. They are not necessarily consistent, for example sometimes there will be a reference to the original manufacturers part numbers,casting numbers, or stamped numbers and sometimes no reference at all. If you can locate a parts book which covers your year and size of truck, I would buy it. You can learn to read it as you work on your truck, good luck.
If it is determined that the second line is what's making the mess, plumb that line into a larger tank/resevour that sits next to the MC and let it gravity feed back into the MC. The big tank can have lots of extra air space to handle the surge.
Hy HFfarms, yes there are parts books they usually cover a range of years and are usually split into light trucks, medium duty trucks and heavy duty trucks. They can be a mystery until you learn how to read them. They are not necessarily consistent, for example sometimes there will be a reference to the original manufacturers part numbers,casting numbers, or stamped numbers and sometimes no reference at all. If you can locate a parts book which covers your year and size of truck, I would buy it. You can learn to read it as you work on your truck, good luck.
I will keep my eyes out for this specifically then, appreciate the input.
Originally Posted by Mike B
If it is determined that the second line is what's making the mess, plumb that line into a larger tank/resevour that sits next to the MC and let it gravity feed back into the MC. The big tank can have lots of extra air space to handle the surge.
Mike B
Not sure how, but Napa located a fresh 12.75" hydro-vac for about $130 and it is on its way now. As to the slosh, it appears to be due to the lack of cap seal, and a new MC should solve it. Currently tracing a modern part number for this MC.
For anyone reading this thread in the future, closer inspection of the MC yielded part number 5462223 as a Delco Moraine 1 1/4" bore. So not only is the master a two line unit, it is a larger single bore than standard. So in conclusion, these trucks had an optional factory upgrade to a 12 3/4" Bendix Multi-vac which must then correspond to a unique master cylinder with larger bore and second return line inlet. To tell if a truck has this package, inspect for a second 5/16" line dropping out of the master reservoir and running to the hydro-vac. I do not know the RPO for this option right now. I will try and dig it up however.
Additionally, part number UP2474 is the maxi-pack that is needed for the 5k lb front axle brakes for this truck (60-65 C60). Part number is listed for the C50 lines but interchanges with the C60. We inspected against the hardware I removed and all matched up. The only thing the pack doesn't have is the lower shoe retaining spring that sits above the manual adjuster. I should have the fronts together this evening and will disassemble the rears and report back on sizing to begin the hunt for rear brake parts.
My 1964 C-60 has the second line coming back to the master cylinder. It is my understanding this is a return from the hydrovac.
That it is. In direct words from the books, "the function of which is to compensate for for any loss of fluid from the Multi-Vac hydraulic cylinder."
It also means you have the optional factory brake upgrade with 12.75" hydrovac unit and the larger 1.25" single bore master. The hydrovac can still be sourced, but no luck on even a rebuild kit for the master. (Part # 5462223). It would appear that once worn out, you have to convert to a different setup unless you are lucky enough to track down a NOS master, which are around but very hard to find.
Hy HFfarms, I am a mechanic, not an engineer and I don't profess to be one. The fact that I have never seen this brake line plumbing system until you showed us your trucks system sets a red flag in my head. Over the years there have been many different things tried in the field of vehicles, some ideas were good and have continued and been refined and improved. The fact that this particular system was/is not in widespread use tells me it was not something that added a benefit to to the more common single application to the brake booster system. As I said previously, if it were my truck I would remove the second output line from the booster back to the master cylinder, plug that port on the booster and run the system with one output from the master cylinder and one output from the brake booster to the braking piping system. As that is the system we are more used to seeing in a single braking system I think it will work fine. It is your truck and you may restore/rebuild it as you see fit, please verify that whatever system you decide on is safe before you venture out onto the road.
Hy HFfarms, I am a mechanic, not an engineer and I don't profess to be one. The fact that I have never seen this brake line plumbing system until you showed us your trucks system sets a red flag in my head. Over the years there have been many different things tried in the field of vehicles, some ideas were good and have continued and been refined and improved. The fact that this particular system was/is not in widespread use tells me it was not something that added a benefit to to the more common single application to the brake booster system. As I said previously, if it were my truck I would remove the second output line from the booster back to the master cylinder, plug that port on the booster and run the system with one output from the master cylinder and one output from the brake booster to the braking piping system. As that is the system we are more used to seeing in a single braking system I think it will work fine. It is your truck and you may restore/rebuild it as you see fit, please verify that whatever system you decide on is safe before you venture out onto the road.
I completely agree to a point. The fact that it is factory makes me breathe easy, and the stopping power of the bigger hydro-vac I see as nothing but a good thing. It could be that as a factory upgrade, it came with a price tag that most buyers didn't care for, and thus it is not as common because of it. Much like the quadrasteer silverado's of the early 2000's as an example. Not common, most look at it cross eyed, but it is arguable more bullet-proof than the standard 8.5" ring gear straight axle and allows significant increase in capability. Most just didn't want the $2k price jump for it to be installed, and opted for the standard route instead. Maybe these brakes are of a similar situation. Money is a great motivator.
As an engineer, I can appreciate the system, but I don't fully understand the need for the return. My only though it that it somehow uses a progressive capability that requires more fluid when heavily loaded with more brake pressure, and thus bypasses a variable amount back to the master at lesser loads (less pedal travel). BUT, i do not understand the exact physics of this unit so this is only a hypothesis.
Regardless of it all, I have a new 3 line hydrovac in my shop, and the master is being disassembled and cleaned for inspection and reuse. Should everything check out, its going back in. Should it not, then due to lack of parts, we are going the single line route with the spare unit I have here. Either way, brakes will be 100% before this truck moves again, I can promise anyone that. Ive lost 3 vehicle in my life to brake failures, so I don't mess around with it. Aint no kill like overkill when it comes to brakes.
The master and likely everything else can be rebuilt by someone like Brake and Equipment Warehouse in Minneapolis, https://brakeandequipment.com/ . Call them, do not go online and expect to find the answers for this old stuff. They have all the parts and the expertise to bore, reline and rebuild anything. No, I am not affiliated with them in anyway and I am sure there are other outfits like them scattered all over the country, likely the world. I have not seen them stumped yet. They almost certainly are familiar with this double line thing and have the answer as to what to do with it.
Here is what they say about themselves:
We have been supplying the Upper Midwest with quality auto and truck parts for over 55 years. We started as a brake specialty warehouse and have evolved into a full line automotive warehouse as we continue to meet our customers' needs. Located in the Beltrami neighborhood of Minneapolis, just off of Central Ave and Broadway Ave, we are able to serve Minneapolis and the surrounding area quickly and efficiently.
Our award winning machine shop separates us from the competition by offering custom friction work for hard-to-find classic automotive parts to industrial friction application. We do in-house, plasma cutting, custom brake hose and brake lines, brake shoes rebuilding (bonded/riveted), brake shoe arcing, flywheel grinding and cylinder sleeving for wheel cylinders/master cylinders and calipers and of course drum and rotor turning.
455 HARRISON STREET NE MINNEAPOLIS, MN 55413 TOLL FREE: 1-800-233-4053 TEL: 612-378-3141 M-F: 8:00AM — 5:00PM SAT: 8:00AM — 12:00PM
Mac :{)
1962 K10 short step side, much modified for rally 1969 T50 fire truck, almost nos, needs a few things
I gave them a call sweepleader. After 30 minutes of conversation, they are stumped. I fired over a myriad of photos of the unit and they are going to talk with the machine shop to see if they can possibly rebuild the unit.
The specific part number cross references to a dual piston master for some reason in their books, and this single 1 1/4 master is a ghost to them. But, they are looking to see what's possible. I'll report back with what they find/determine.
I found a replacement as well, but it's NOS, and Lord knows those seals are dry-rotted as heck by now, so even a NOS unit would be in the same boat.
Wow, that is the first time in about 40 years I have heard of them not saying, "sure, we can fix that." !! Well, your situation must be even more rare than I thought it would be after you said you had found reference to it in the manual.
Do pass on what you find.
I don't know where you are located but you might check around for other places that do serious brake work, maybe someone else in the business is aware of these and how to deal with them.
Mac :{)
1962 K10 short step side, much modified for rally 1969 T50 fire truck, almost nos, needs a few things
Closing the loop on this thread with updated information and new outcomes. Update moved to new thread for cleaner presentation and consolidation of information and more easily searchable title for future reference by others.
