Front Brake Question

[tbh726]

thanks great information, yes i had wondered about the flexible brake lines... i purchased replacements and figured to replace just because i was slowly replacing all rubber items (fuel, heater hoses, ect) figured they might either be old or rotten. the flexible lines do not look like they have been replaces so i assumed they were original. On the cotter pins, is this the one's https://www.ebay.com/itm/125310055887 or do you get them at someplace like Napa? yes will go slow, never packed bearings, watched people do the hand packing in the past, but will look for the tool.

how do i know if a bearing is "bad", thinking of the outer one you mentioned that you just repack it on the spindle if it is good enough...

is this good grease to use? https://www.amazon.com/Lucas-Oil-Red-Ta ... 140&sr=8-6


tim

[rickf]

Those cotter pins are perfect as long as they are long enough. I would have to look them up in the manual to see what is called for. As far as grease, any NLGI #2 grease will work just fine. If you get the bearing packer that uses a grease gun to do the work it is easier to just use the same grease that is in your grease gun for all of the grease fittings.

[Lou]

This is where I purchased the cotter pins from. The tm actually specifies the AN (aircraft) part number. This is no place for harbor freight cotter pins, lol!
https://www.aircraftspruce.com/catalog/ ... 65-287.php

[hondo100]

Spruce is a great place for small quantities. I found B and B Aircraft Supplies has some small items like screws and cable clamps that Spruce doesn't carry.

http://www.bandbaircraftsupplies.com/

RG

[m3a1]

As to bearing wear, just google tapered roller bearing damage (google images) and enjoy looking at the wreckage. There's a lot that can go wrong with bearings and what can go wrong WILL go wrong. Since bearing inspection is, for the most part, visual, it doesn't do much good to discuss it in text.

These sorts of bearings can have a lot of time on them and still look new so, I would say the general rule of thumb is, if you see anything that looks out of the ordinary (for a new bearing) then that's going to be trouble.

So, the first thing you must do is organize them so you know for a fact, which bearing belongs with which race (they wear into one another). The second thing you must do is clean them thoroughly. Diesel works pretty well if you don't want to go out and buy solvents.

Here's a time-saving tip - The races are the quickest way to get an answer as to the health of the bearing and race without a lot of clean-up work. Sometimes, a thorough wipe-down of the race will allow you to see if it looks like junk. If it looks like junk, don't bother cleaning its mated bearing because that's going to be just as junky.

Cheers,
TJ

[m3a1]

Since you asked about packing bearings...here's a decent soup-to-nuts article that does a good job covering the topic.

https://knowhow.napaonline.com/dirty-jo ... l-bearing/

Cheers,
TJ

[m3a1]

how do i know if a bearing is "bad", thinking of the outer one you mentioned that you just repack it on the spindle if it is good enough...

is this good grease to use? https://www.amazon.com/Lucas-Oil-Red-Ta ... 140&sr=8-6


tim

Frankly, I use the best bearing grease I can reasonably afford. I am very fond of Lucas lubrication products, and Timken, because I reckon the people who MAKE bearings probably ought to know about bearing grease. Tacky grease simply means it's sticky and that's good because you want it staying where you put it.

If your MUTT sees casual use and isn't being dunked underwater (ahem...like some people we know!) you can get away with just about any name brand and have decent results. A bearing grease's ability to repel water should be on the label. If the manufacturer makes no claim in that regard, I generally won't buy it.

You might have guessed I am not a fan of submerging any vintage vehicle because there is a lot of maintenance required afterwards (provided the owner actually cares)....but that's a soapbox for another time.

Cheers,
TJ

[ccdoran]

Excellent information, all! Thank you all for sharing!

[tbh726]

wow how time has flown... I finally got time to start to look at these brakes. I cleaned both front brake up with cleaner and found a few things... one the brake lines are not attached to the frame at all. two i could not even get the lines loose they seem frozen. I do think every thing cleaned up, i did see one rubber seal that is warped and torn. I was planning on replacing all of the rubber lines, but could not get them loose. So now i am going to replace the lines for sure in the front from the T connector to and including the rubber lines... i did still take it out for a spin and the brakes seems a 1000% better.

So a couple of questions
1. does anyone see or note anything that i did not state?
2. i have new brake shoes, springs should i replace them, i do not want to replace parts just because i can.
3. what about wheel cylinders ?

[Horst]

Tim,

A few comments:
1. Lift the 2 dust caps per each wheel cylinder and check if there is an excessive amount of brake fluid behind them. If yes, at least new cylinder seals are in order. You can do this check with everything in place. I personally would replace the wheel cylinders anyway. Right time to do and not too expensive.
Try to get original parts, not repro cylinders from Asia. The good ones have that red color and also a label "only use on M151A2 front" (something like that).
Other than that I see no reason to change the brake shoes or any spring. As said before assuming they are not contaminated with fluid or oil/grease.

2. Check your all your solid brake lines hidden under the textile webbing. Unfortunately it tends to hold moisture and the line is in much worse condition than what you see. So you might want to replace more lines than you already decided on. Use a quality brake line wrench to unscrew the lines, don't try a normal open wrench. At the wheel cylinder you will most likely toss the brake line anyway, cut the brake line and use a socket to unscrew it from the cylinder. Same at the T-connector.

Remember, this is a single circuit brake system, so no redundancy if it fails somewhere...

P.S.
I do repeat myself, but as you already have the hub removed, remove the wheel drive shaft entirely (just 4 nuts) and you can grease the bearing plus you can check the condition of the universal joint. I bet it is dry and rusty. If those universal joints are not lubricated properly, they will fail. We have a member where the failing joint took the brake line with it and only thing left he had was the emergency/hand brake.

[rickf]

These are your brakes. As Horst said it is a single stage system so if any line breaks you lose all of your breaks. You "can" pull the parking break but it "will" lock up the rear wheels through an open differential and we all know what happens to an m151 when that happens. Instant sideways and over it goes. You do not want to lose your brake system. I always replace the entire system on any new to me vehicle I get. That way I KNOW for sure that what is on there is correct and in perfect condition and will last a very long time. I can see in those pics that some of the shoes are contaminated so you have had wheel cylinder leaks or wheel seal leaks. Either way the shoes are junk.
I will not always replace the master cylinder but I plan on it no matter what. And I ALWAYS flush it out with whatever fluid I plan to use in the vehicle. The problem with not replacing the master cylinder is that the lower portion of the bore below where it is normally used will be rusty. So as soon as you bleed the system and push past that rust you have damaged the seals and pistons.

Brake fluid is another concern, Most people will tell you that you HAVE to run DOT5 silicone fluid in a military vehicle. You do not. You can run any normal brake fluid you like, you simply cannot mix them. So when you replace all of the wheel cylinders it is the perfect time to change fluids if you are going to do it. I personally run DOT3 in all of my vehicles. It is easy and cheap to find anywhere and it holds moisture in suspension so that way when you flush it out every other year as you should all the moisture comes out with the old fluid. With DOT% silicone fluid the moisture migrates to the lowest spot in the system, which is the bottom of the wheel cylinders where it cannot be flushed out without disassembling the wheel cylinders.
Personal preference on that subject.
But on the subject of the actual hard parts I say replace all of it. Check the lines very closely and replace the metal lines also if needed. And replace anything made of rubber on the vehicle. Belts, hoses, brake lines. If it is 20 years old it is bad. All of these parts are still available, as was said try to stay away from Chinese parts, in most cases they either do not fit or are as bad as what you are replacing. Chinese electronics are exceptionally bad.

[m3a1]

That one return spring looks like it's all bent out of whack. Goodness!

[tbh726]

thanks for the info guys guess i am replacing it all, i do not want to replace parts just to do it, but i do want to be as safe as i can... can someone tell me if these are the parts i need?

wheel cylinders is two 1 and two 3/4 correct they are not all the same on the jeep?
https://www.ebay.com/itm/171281930764?_ ... 0903.m5276

lines
https://www.armyjeepparts.com/p-2712-m1 ... manuf.aspx

Rickf - it also sounds like i should just switch to Dot3 fluid - if i do switch do i loose any features in the mutt? does it affect if i get in water?

i have new rubber lines i bought, but now i am worried they are junk. they say made in japan and seem to be metric size, so i am guessing they will not fit the wheel cylinders or the lines is that correct?

[rickf]

I strongly suggest you look here at their parts first. https://www.ebay.com/str/redriverpartsandequipment. They will be factory US parts. The brake fluid will not change the feel or function of anything. What nobody tells you is if you ford the vehicle through very deep water is that all fluids, ALL FLUIDS, need to be changed. There are also procedures that are supposed to be done before going into deep water and then undone as soon as out of the water. If you do not have the full set of manuals I strongly suggest you get them. All of the driving and fording info will be in the -10 manual.

[Horst]

wheel cylinders is two 1 and two 3/4 correct they are not all the same on the jeep?

Yes, on an A2 the front wheel cylinders are larger than the rear ones.