DIY Brake Fluid Flush / lessons learned

[Alpine06]

Hello fellow Alpiner's,
Yesterday I was able to finish the work on my breaks and I thought that I share my thoughts with you in case you think you want to do a break fluid flush yourself.
#1 All I wanted to do (originally) in this project was to flush the fluid out / so bleed the breaks. Upfront I like to state that my breaks work fine but I know about the danger of dissolved water in the break fluid and I have no reference date when this service was performed last ... looking at the color probably a loooong time ago. BTW there is a simple tool that you can buy for cheap that measures the break fluid water contend hence it's boiling point. I read some statements on this forum to stick your finger into the reservoir and if the fluid viscosity is like honey then it needs to be changed - that is actually complete nonsense. If you find this condition you are probably overdue by 10 years.

#2 Break Fluid
Our coach can use DOT3 or 4 no other number the modern silicone based fluids are not compatible with the seals in our break system.
I used DOT3 ... only because it was "buy one get one free", but you should use DOT4 as it is less hygroscopic. Also it needs to be an unopened fresh container.

#3 You will need your preferred method of changing this fluid, this can be the old way of pumping the pedal and a second person operating the bleeder, or a vacuum pump, or a pressure hook up to the front reservoirs. Actually we have a third option on our coach and that is to activate the booster pump. I have a vacuum pump so this is what I used.

So far the plan here comes reality:
Check your Jack and Stands are they up to the job? Mine were not and I purchased a 20t jack. I used oak blocks to block the house up and to rest the axel on.
Removing the lug nuts - I sprayed penetrating oil on a couple days before and used my electric impact wrench (Harbor Freight Earthquake) and it busted all of the rear once loose fine. However I just had new front tires installed and the shop did not torque them down and Joe Schmoe just used the 1" air impact to make em tight.
I bought a 3/4" breaker bar and a 5ft steel pipe and was able to loosen them.
The next step I deem very important: I use a garden hose and spray everything down with water. The reason is that even so there is no asbestos anymore I do not want to breathe break dust while working on them.
I have done quite some break's in the military as I worked in the Tank Battalion (lucky me only on stuff with wheels) so I got super upset when I broke off the first bleeder nipple. I took the caliper off and drilled it out but was not happy with my repair and ultimately ordered a new Meritor caliper.
There is a reference on the ACA Site that list the wrong nipple.
I attach a picture with the one that is correct & Meritor Part#
These come in a pack of 10 so I changed all of them out as I went. However I had to heat every single one of them with a torch to break them loose.
Next is that you will find out that the break fluid reservoirs is not accessable to simply poor the fluid in. I used a hand crank pump called Kwik-Fill Fuel Pump its really small and I like that I can crank it backwards so there is not a single drop coming out the front spilling on the generator paint.

I looked at the break pads before and deemed them in good condition with 90% life left ... well I got a good surprise when I took the caliper off. The pad was severely cracked. (pic attached). So in the end it was good that the nipple broke off otherwise I would not have taken a pad out and see its condition.

I purchased new pads for the front and back in the back I placed original Meritor pads and in the front I used Raybestos. The front once looked much better and had only small cracks. I think a break pad from NRS would be the best option for any coach as they have a Zinc Plating and will reduce the corrosion better as any paint. They cost about $40 more per set.
My rear left inside tire always ran hotter and my explanation has now changed a bit as I think that the sever crack in the pad expanded the pack in that area and it always had drag causing everything to heat up a bit more.

Also I was surprised to see that the phenolic piston looked like band new. Not even a hair of a groove nothing - however the caliper bore had its zinc plating worn off in several areas. Not that this would warrant an exchange but I found this interesting.

So I think that my wife is even more happy than I am that we got this project completed as it took us quite a bit longer than originally planned.

Joerg

[lazybyrd]

Thanks for the info

[wolfe10]

Wow. Unusual to see that heat damage/cracking on fixed caliper disk brakes.


Common on the "lazy side" of sliding caliper disk brakes (early Alpines) if caliper slides are not kept lubed.

[LETMGROW]

I used one of these kits in my shop and saved many caliper replacements:

https://surrauto.com/kits/bb007/
Lynn

[Alpine06]

Originally Posted by wolfe10

Wow. Unusual to see that heat damage/cracking on fixed caliper disk brakes.


Common on the "lazy side" of sliding caliper disk brakes (early Alpines) if caliper slides are not kept lubed.

I think you are spot on I also thought that both rear brakes had seen too much heat. So either the person driving misusing the break or the piston is stuck. This is why I went through the effort to disassemble the caliper and found that the piston moved freely.
Another point is that the semi-metallic break pads are receptive to corrosion and usually there is really no application were a break pad lasts for over 10 years ... accept in a coach. So possibly the rust migrating intot he pad had something to do with it as well - not sure.
All other pistons I could push back with small effort no clamp or any tool necessary.

[Alpine06]

Originally Posted by LETMGROW

I used one of these kits in my shop and saved many caliper replacements:

https://surrauto.com/kits/bb007/
Lynn

... and the set also contains 4 of the right bleeder screws. I have heard good things about it but never had an opportunity to use one myself.

[LETMGROW]

Originally Posted by Alpine06

... and the set also contains 4 of the right bleeder screws. I have heard good things about it but never had an opportunity to use one myself.

Before anyone runs out and buys this kit I need to tell you there is no guarantee it will work on every stuck bleeder. I had good success but every now and then I'd get that pesky bleeder which was married to a caliper and was inseparable. Then it came down to whether just replacing the caliper was more economical than spending the time attempting to remove the bleeder screw.
I would say I had about a 90% success rating with the kit.
Living up here where salt is spread liberally on the roads even when it's not snowing, brake bleeders are difficult to loosen after a vehicle is anymore than three years old.
We loosened the brake bleeders on every brake pad replacement job to force the contaminated fluid out the bleeder instead of forcing the piston back into the caliper housing and contaminating all the fluid in the braking system. The dirtiest fluid and the most moisture anywhere in the braking system is always between the backside of the caliper piston(s) and the caliper housing.
After everything was reassembled the braking system got a thorough bleeding to insure the fluid in the system was clean.
Lynn

[Alpine06]

Originally Posted by LETMGROW

Before anyone runs out and buys this kit I need to tell you there is no guarantee it will work on every stuck bleeder. I had good success but every now and then I'd get that pesky bleeder which was married to a caliper and was inseparable. Then it came down to whether just replacing the caliper was more economical than spending the time attempting to remove the bleeder screw.
I would say I had about a 90% success rating with the kit.
Living up here where salt is spread liberally on the roads even when it's not snowing, brake bleeders are difficult to loosen after a vehicle is anymore than three years old.
We loosened the brake bleeders on every brake pad replacement job to force the contaminated fluid out the bleeder instead of forcing the piston back into the caliper housing and contaminating all the fluid in the braking system. The dirtiest fluid and the most moisture anywhere in the braking system is always between the backside of the caliper piston(s) and the caliper housing.
After everything was reassembled the braking system got a thorough bleeding to insure the fluid in the system was clean.
Lynn

Lynn,
I can tell you are doing this for a while and follow best practice. I first bleed all the old crud out and then pushed the piston back for the new break pad. There is no sense in getting that old crud pushed back towards the ABS System. It would be nice to have someone like you to do service as one will know that you do it right. Unfortunately you are the minority of service techs out there today. I think most places are plagued with high turnover and the quality and pride of doing the job right is just not there.

[KiteSquid]

Great tips here!!!!!

Don't forget to change the brake fluid in all your vehicles every year!!!!!

[wolfe10]

Originally Posted by KiteSquid

Great tips here!!!!!

Don't forget to change the brake fluid in all your vehicles every year!!!!!

Please post a link to recommendation for "every year" brake fluid change.


Thanks.

[KiteSquid]

My vehicle owners manual says every other year...

My motorcycle statede annually.

I go with a little overkill......

[Alpine06]

Originally Posted by KiteSquid

My vehicle owners manual says every other year...

My motorcycle statede annually.

I go with a little overkill......

You can spend $10 on a little tester and you will know when to change it. There is also one for $20 if you search a little on Amazon.

[Old Scout]

…..observation: over the years, I have changed flushed and changed the brake fluid on my 2003 Alpine 4-5 times. I have also flushed/changed fluid on maybe 7-8 other Alpines over the period, eg, in conjunction with master cylinder "upgrade." In nearly every event, I have encountered rusty rear bleed screws in the rear calipers but little or no rust in the front calipers. "Suspect" [but cant prove it] that front calipers tend to heat up more than rears so moisture is less likely to accumulate?????? Either way, flush/fluid change every 2-3 years, especially in humid climates, is probably a good idea.

[KiteSquid]

Originally Posted by Alpine06

You can spend $10 on a little tester and you will know when to change it. There is also one for $20 if you search a little on Amazon.
Attachment 267111

It is in my cart. Thanks.