need-a-t2

iTrader: (9)

Ever since I bought my S5 turbo the ABS unit has leaked. So after failing my yearly state inspection for it, I figured it was finally time to tackle this project. Mazda specifically states in the FSM that the ABS unit is not serviceable and no one sells rebuild kits for them, so I decided to try and cobble my own together. So this thread will document my adventure and hopefully help out others with leaky ABS units. So first things first removal. There are 5 barke lines, 2 connectors, 1 ground wire and 3 bolts that secure the ABS unit to the car. So here she is removed from the car



My unit was leaking from the bottom of the 3 solenoids. Disassembly is fairly straight forward. The relays pull right out and the electronics tray is secured to the motor with 4 phillips head screws.


The motor is removed by removing the 4 bolts holding it on. After removing this, I realized i didn't really need to remove it, and putting it back in was a PITA.


Onto the good stuff. The main body is held together with one giant M12 bolt. once the bolt is removed, you can use a rubber mallet and tap the two halves apart. I highly suggest labeling the solenoids and the location they came from. Once apart they all look the same.

need-a-t2

iTrader: (9)

Ok, so onto the repair. These are the orings I bought. I got most of them right from mcmastercarr, but had to source the 22mmx1.5mm elsewhere. You can order them lots of places but be sure to get EPDM rubber.


Please note the 17x2.5mm orings are x rings and are not round. This is the location of the 17x2.5 orings. In the center hole where the bolt threads into, there is an internal oring. that's where the 17x2mm oring is installed.


On the top side of the casting the 4x2mm orings are installed.


The dowels have orings on both sides that take a 5x1.5mm orings.

need-a-t2

iTrader: (9)

last but noy least I put the 22x1.5mm orings on the top of the solenoids. These orings are viton, and i'm guessing i'll have to replace them eventually. If you do this buy EPDM! Also note there is a small rubber washer on top of the solenoids. I reused these as they are specially washers and not easily sourced. Good news is that i'm 99% sure they do not actually seal anything and are just a bumper of sorts.


So that's it! Reinstall, bleed your system, and enjoy not having to carry brake fluid in the bin behind you.

If by chance your's is leaking from between the casting and the big motor on the back, there are 2 xrings that seal the shafts inside the casting. I didn't measure them so I'm not sure what size they are. To remove them, there are 2 set screws on the sides of the lower casting. Remove them and you can then push the shafts out from where the motor shaft goes. They are pretty tight, but keep pushing and they pop right out. You'll have to remove these shafts to get the motor back in if you opt to remove it.

Turbonut

iTrader: (1)

Nice write up.
Always wondered the size/quantity of the seals that were needed. Last year found that my original
pump was leaking and wanting to do a delete, was going to rebuild one of the other three I have,
but the leak was noting more than a brake line fitting that needed to be tightened.
Still might just bite the bullet and rebuild one of the others.

DaKeL

Awesome right up, needed to bump this for props.

pfsantos

iTrader: (1)

Nice.

Gen2n3

iTrader: (1)

Great write-up! Sadly, the Part Numbers stamped on the packages do not cross to anything.

To the OP:
Is this the correct list of o-rings needed for this repair?
1. 22x1.5mm
2. 5x1.5mm
3. 4x2mm
4. 17x2.5mm (X-ring)
5. 17x2mm

What quantities are required?
Are all o-rings made of Viton or EPDM?
How has the ABS unit held up after the repair, 1.5+yrs later?

Has anyone else approached this repair with success?

Cheers,
George

smikels

I am curious on this as well. My abs been leaking for some time now.

TonyD89

iTrader: (10)

I think he spells out pretty good, buy extras if you're not sure, they're just freaking o-rings for Christ's sake! I'll add to make sure you use EPDM rubber for anything that could touch brake fluid. He said he used Viton on the outside of the solenoids. I wouldn't if I could avoid it. Don't forget there are some of the X-type o-rings in specific places. Re-reading does wonders on the understanding of what's going on.

pfsantos

iTrader: (1)

No need to be an *** (part of your post).

You're missing the point. It's not the o-ring cost or getting more of them that's being asked, it's making sure you have the right ones because of the labor involved and not wanting to redo the job.

For ***** and giggles, I tried searching the part numbers. Nothing comes up on the McMaster-Carr site.

Maybe the OP can post the McMaster-Carr numbers?

need-a-t2

iTrader: (9)

Sorry guys, i didn't get any notification that people has responded to this! Mcmaster part numbers are:

Multipurpose O-Ring Steam-Resistant EPDM, 2mm Wide, 17mm ID : 1172N65
Multipurpose O-Ring Steam-Resistant EPDM, 1.5mm Wide, 5mm ID : 1172N44
Multipurpose O-Ring Steam-Resistant EPDM, 2mm Wide, 4mm ID : 1172N77
x-profile, buna-n, 2.5mm x 17mm : 1200N166

these come in packs of 100 with the exception of the x-rings which are still a 10 pack. Order 1 package and you'll be set for life

I sold the car a few months ago, but as of that time it was dry as a bone.

Pete_89T2

iTrader: (4)

OP - Nice write up, wish I had seen this some 17 years ago when my ABS pump started to leak! Anyway, back then I basically did what you did and took the pump apart in hopes of being able to source new seals, rebuild it to be leak free and functional again. Ended up doing the ABS bypass instead because: (1) I couldn't determine with absolute certainty what cross section shape & size those "X" rings were supposed to be - let alone find a source for them, and (2) Chucking the ABS pump was a big weight reduction, and since these early ABS systems were only 3 channel and generally sucked anyway, I didn't mind doing without it.

Curious to hear how you cracked the code on my problem #1 above - my "X" rings were so worn out that I literally couldn't tell what shape the cross section was supposed to look like. What did your old X rings look like when you pulled them out?

smikels

Thanks need-a-t2 for the information! I will be ordering today hopefully so I can take off my ABS and replace the orings! I didn't really want to delete the ABS unit if I didn't have to. Mine has leaked since I got he car over 4 years ago. I am willing to give this a try now!

O-Rings ordered!

Ships today
Multipurpose O-Ring
Steam-Resistant EPDM, 1.5mm Wide, 5mm ID
1172N44
1-Pack of 100 each
$3.04

Ships in 1–3 weeks
Multipurpose O-Ring
Steam-Resistant EPDM, 2mm Wide, 17mm ID
1172N65
1-Pack of 100 each
4.77

Ships today
Multipurpose O-Ring
Steam-Resistant EPDM, 2mm Wide, 4mm ID
1172N77
1-Pack of 100 each
2.84

Ships today
x-Profile Oil-Resistant Buna-N O-Ring
2.5 mm Wide, 17 mm ID
1200N166
1-Pack of 10 each
11.50

Gen2n3

iTrader: (1)

Need-a-t2,

Thanks for responding, listing the part numbers, adding clarity to your original posts, and sharing your experience after the repair. Too bad that you had to part with that FC.

I do have one additional question based upon one photo: are the 22x1.5mm o-rings for the 3 solenoids round or squared off (x-ring) (in post #3)? They look x-ring shaped.

**Break, Break**

Tony, I appreciate the reply but I am curios on two things: How did your repair go and what did you use?

Cheers,
George

smikels

Gen2n3 if you want to tackle this project together I am game as well. Or if you just want some o-rings since they come in pack of 100.

need-a-t2

iTrader: (9)

Thanks, I'm happy to see others trying to restore these pieces of history. The S5s are getting harder and harder to come across and really need our love!

I didn't try measuring the orings for most of them, I just measured the mating seal surfaces and extrapolated the diameters and thicknesses from that. I think the 17x2 oring was the only one I actually tried to measure. But as far as my old "xrings" mine were in one piece but had visible damage to them. To that point, I don't think the originals were square, but were severely deformed orings, which is probably why it was leaking in the first place.

They do look square, but like I mentioned above, I think the originals started life as an oring, but under the heat, pressure and time have permanently deformed to fit the gland they are installed in. If you look at the "top" of the two black orings in post #3 you'll see they are very curved, which isn't a sure sign of anything, but it has more curvature that I would expect from a deformed square ring.

Gen2n3

iTrader: (1)

Smikels,

I could lend a hand. Before I jinx myself, the ABS unit in my Vert is not currently leaking *knock on wood*. My interest in this thread is more for reference and future use. Shoot me a PM and we'll see about tackling this project. An extra set of hands goes a long way on projects like this.

Need-a-T2,

Thanks again for verifying the shape of those 22x1.5mm o-rings. I couldn't agree with you more about maintaining the 2nd gen RX-7s (or any generation for that matter)!

Cheers,
George

TonyD89

iTrader: (10)

I got rid of the ABS pump. I've worked on brakes for a long time (shade tree, my own cars, I'm old). The thing to remember is real rubber whatever, washers, o-rings, piston seals. Brake fluid will destroy silicone, Viton, and buna.

smikels

So I completed this finally. I was a little worried about such an old car and getting this part apart and back together. I have been wanting to do this after I saw this post and saw it was not that long ago that need-a-t2 completed his. I hope it will be leak free for a while. The 2x17 mm o-rings took quite a while to get here. I actually ordered a second batch of 100 because I thought maybe it did not go through. Anyways the biggest issue I had was taking that M12 bolt off. This is bigger then the standard sets you have probably so you may need to get this allen wrench. I bought one at the local Oreillys. I had to put it in a vice and use a breaker bar. I did not take the motor off. I only pulled the electronics black cover side off so you can separate the pump. The other issue is when you put the ABS pump back is to connect the line that is close to the wheel well before you get the pump settled in as this one is hard to get to and get connected. It is easier to remove this one last as well when you can move the pump around a little to get to it. It is just really close to the engine bay.

O-rings used
5x1.5 mm qty: 8 Leftover : 91
4x2 mm qty: 3 Leftover: 97
2x17 mm qty: 2 Leftover: 198
2.5x17 mm qty: 3 Leftover: 7

If you want some of these o-rings message me. The only ones I might not be able to give you are the 2.5x17 since it only came in a pack of 10. But really it is only around $20 to get all of these from McMaster Carr Supply as well. The only issue was the over a month wait for the one oring. Some of the passage ways on my pump were gummed up. I used a pick and cleaned them out. I also used a green scratchy pad to help clean the surfaces. When completed I just bleed the brakes and all is good. I will keep an eye on the reservoir to make sure it stays full. It will be nice with the ABS pump not leaking all over and causing the car to rust on that side.

Thanks to the (need-a-t2) for the write up. Makes it easy to follow.

need-a-t2

iTrader: (9)

glad to hear another one is fixed and leak free....i'm not just a fluke of luck!

mr_vaughn

iTrader: (1)

I just tried this..I could not get one of the dowels out of the top head.... I have bent the dowel and looking for a used ABS unit..

smikels

Ohh wow yeah I had a couple dowels that were pretty tight as well. I used Vice grips to grab them and twist them out. It only scratched them a little when grabbing.

mr_vaughn

iTrader: (1)

I used a vice grip too but had to heat it up with a torch a little to get it loose and it came out then pretty easily.
I should have done that in the beginning rather than trying man handle it.

No_love_for_pistons

iTrader: (4)

Wish I had known this prior to removing my abs pump a few years ago. Great writeup OP!

need-a-t2

iTrader: (9)

thanks. i'm glad its useful!