Cat 420D needs brakes getting weak, anyone have a how to on this issue?

[rampking]

Hey guys looking to change out the brakes on my 420D, they seem to be getting a little weak and would rather get on it now before its to late. Is this a big job? Anyone have a hopw to on this?

Thanks
king

 

[alrman]

Getting weak? - Not sure what that means rampking - Is the pedal height falling? Is pedal still good & brakes just not pulling up? How many hrs on machine? When was the last oil change on the rear axle?

 

[rampking]

Hey,

I guess it feels like I have to push harder on the pedal....I just changed out the rear diff oil 2 weeks ago, it was dark and had a light skim of sludge on the drain plug. It's a 2004 with 4000 hrs. I have read as much as I could find on the problem with the brakes on this thing, and I have no vibrations when roading and I have so slipping when adding power. So I hope the rear diff isn't stripped. Is the brake job a big deal?
Rampking

 

[alrman]

What oil did you use? Cat recommend an additive that goes in with their TO-4 oil -

I've done a few at around those hrs......
Axle needs to be removed to do the job. Some guys refit a wheel & stand the axle vertical on the wheel & do one side at a time. Personally I like doing them on a bench.
Have had to buy friction discs & backing plates & even the housing that contains the brakes in the axle - due to friction material worn away & resulting in steel on steel/cast.

 

[rampking]

I used the recommended gear oil from Cat with the additive they gave me...can't remember what it is. But the guy was pretty adamant about adding the additive......so your telling me I need to remove the rear axle of my backhoe to replace the brakes???? That's just awesome! I have little experience working on heavy equipment...I dunno if I got the jam to do this.....there goes this months profits, after Cat Dealer fleece's me for this.

 

[Lee-online]

It is a simple job. Pull the axle, split the end housings from the diff section. Replace the friction disks and probabley the disks between. If you let it go too long it can wear into the housings.

Reseal the pistons while it is apart.


The oil is MTO with the additive, either Cats or new hollands.

 

[rampking]

Simple for you maybe...I am not afraid to say that tearing the axl off my backhoe is above my head. How long do one usually get out of these brakes?when has everyone swapped out there first set round abouts?

 

[Lee-online]

I have seen them worn out at 3000 hours and still on the originals at 8000. It all depends how the hoe is used.

I would say it would take about a day to do the brakes.

 

[jmtrackworks]

What is the guesstimation on parts for a repair like this? I have a 416c.

 

[Cmark]

The oil could either be MTO or TO-4 30w, plus additive, depending on your serial number.

 

[jmtrackworks]

What is the guesstimation on parts for a repair like this? I have a 416c.

Price I mean

 

[alrman]

Price I mean

Parts last time I did one (will depend on your buying price at dealer) - all discs & retaining housings x 2 & all seals req, inc brake pistons - $1500 - $2000. Does not include bearings if required add $600 - $700.
I would allow at least, a couple of days to do the job - allowing time to order & aquire parts needed.

 

[caterpillarmech]

It is not a tuff job. Pull drive shaft, brake lines, wheels and mounting bolts and it is out. Brake chambers are seals by one or two big orings and disc and plates just drop in. You and a buddy can do it in a day. And yes 197-0017 friction modifier is for the cat/new holland brakes other wise it sound like a dying animal when stopping.

 

[DGODGR]

I have done it 2x on my 416C. The brakes seem to last about 5,000 hours. It takes about a day with 2 guys. I suggest 2 guys as the rear axle is tough to get in and out with only one guy. When the brakes get worn out you will notice the brake fluid level will go down in the matser cylinder res. the brakes will work but the pedal will continue to depress when you keep pressure. May require pumping as well. I have not noticed any reduced braking performance. When brakes wear out the pistons go so far, trying to push discs against the baking plate, that they push past the seals and allow brake fluid to escape into the rear axle. How come you Cat mechanics are not sharing a few tips? I suggest buying a few sets of the piston seals. It requires a lot of force as they can be tough to get back together (the piston halves). Use lots of assembly lube and I suggest that you have a dead blow hammer on hand. Once you have put the brakes back in, and whichever out board axle housing, use compressed air to check the piston seals before you put the axle back under the machine. If you inject the compressed air into the brake fluid ports, on top of the axle, you should not hear any air movement. If you can hear air it is escaping from inside the piston to the rear axle housing (just like the fluid was when you had worn brakes) which means you have a bad seal. Dis-assemble again, repair seal, repeat check process. I would not do this with out a manual showing you the proceedure.
Originally MTO did require a friction modifier like the Ford/NH units. Cat began placing it in the MTO around 2000. I stopped adding, based on info I got from my Cat dealer, and have zero noise, or any other issues, less normal wear, since. The newer, updated, brake pads contain Kevlar. It is not recommended to use MTO if you are using these newer pads. I don't recall what the new recommended oil is. Consult your Cat dealer.

 

[rampking]

Thanks guys, appreciate the help. I had it looked at by an older man (wiser)he seems to think they are fine, for now. I am gonna keep a close eye on it til warmer temps....I am also gonna do a lot of going over the procedure before attempting...it'll probably be a huge pain to do but I am gonna attempt. What's the worst that could happen?:shf:shf:shf. LoL