FYI, I ordered my O-rings on Sunday with one showing as backordered. I got a notification yesterday afternoon that they shipped, so either they got some more in or that number on the website was wrong.

Dale

I believe people have figured out how to do the newer ABS but it's a pain to try and track down the TON of parts needed to do the conversion.

Also, some of the parts (like the bracket for the pump and the lines) would be designed for a RHD car.

A lot of wiring, engineering, and custom work so you can add 1 channel of ABS.

I wonder if you could use like a later Miata setup or something? It may have some similarities with the later setup from the JDM FD's.

Dale

Hey Matt,

Just wondering how your ABS unit is holding up years after you did the new o-rings. My unit is leaking and I am going to use your writeup to rebuild my unit. Thanks

The link https://oringsusa.com/catalog/index.php/cPath/55 leads to a square ring page that offers three types: "BN70 SQ", "S70 Square" and Viton.
Which ones are we meant to order?
BN70 or S70?
It's unclear from the page what the difference in material is.


EDIT: By process of elimination, S70 (silicone 70) is the only material offered on that website that does not specifically say it is incompatible with brake fluids. Soooo I guess this is it?

The first link seems not to be taking me a place on the web. The second two do.
I looked under "hydraulic fluid" orings and found some MIL-SPEc MS28775 qualified rings. Are these the EPDM ones you used.

Looks like the square rings are Viton

Not sure what the -008 quad rings. For that one, OringsUSA says contact us. There might be a substitute?

Anyone have a good resource for finding these aftermarket ABS bolts? Undergoing a rebuild on my unit and some of the bolts were pretty locked on and stripped out.

Haven’t had any luck finding the proper specs on mcmasters. Got a photo for reference. Looking at the main torx bolts that hold the unit together and the torx bolts that hold the motor on there as well.


https://cimg9.ibsrv.net/gimg/www.rx7...35037a02a.jpeg


-milly

'93 RX-7 Touring. I've been losing brake fluid for a while now and finally tracked it down. The ABS hydraulic unit is leaking. The paint below is blistering as well.

Looks like y'all have had some success rebuilding. How complex is this? I replace my own brake pads, but usually not much more than that. Does this require any specialized tools/equipment? I'm not sure how to go about cleaning all the brake fluid below the unit and leaking down to the wheel well. I knew a good RX-7 mechanic in Texas, but I'm up in Seattle now. Advice?

I've done a few of these now.

Notes:
-Silicone caps to cap the now exposed brake lines so no more brake fluid gets on your paint. Be careful not to bend the lines too much when removing the pump.
-Quality torx bits to not strip the bolts as seen above. Even then some can be a challenge. Easier to crack them loose while still mounted in the car vs trying to do it on the bench.
-Nice set of picks to remove the old o-rings and not scratch mating surfaces
-soft brushes to clean everything once disassembled. Use lint free towels/rags
-Take extra extra precaution on reassembly. It is very easy to not have the orings sit exactly right and once tightened they will either distort or rip and leak. Been there done that.
-Do not over torque the bolts on reassembly! Better to use a small drop of low strength Loctite
-Thoroughly bleed the system afterwards. Might be smart to use cheap parts store fluid to verify no leaks, then flush again with quality fluid.

Overall it's an easy job, just time consuming as nothing can be rushed.

The 1st link is still good and has all all 5 of the EPDM70 o-rings.

The 2nd link has 3 types (sub-pages) BN70 SQ S70 Square Viton® Square - but only the S70 page has any parts listed. Based on the HyperRex post, it looks like this is the right choice?

The 3rd link has nothing. That's for the -008 quad. Is there a substitute?

Jim,

I ordered that -008 quad from Sterling Seal and Supply. Found them online, company out of NJ. They have a $25 minimum I believe so maybe you could source the other o-rings from there also.

I didn’t know about the minimum and site let me purchase just that o-ring but didn’t process the shipment. Ended up contacting them and they were super nice and mailed it out.

Also good tip on cracking the torx bolts from Brekyrself when the unit is in the car. Mine were awful even in the vice. Ruined two bolts.

Brekyrself,

Any recommendations on finding those Torx bolts or do you happen to have any lying around?

-milly

Thanks Milly. I cross-referenced with Sterling Seal. In general, they have a better web site - actual measurements on the o-rings.

Main question: NBR or FKM? Will either of these work? I found this site which seems to indicate that neither is good: https://www.musclecarresearch.com/co...-compatibility

2nd question: Does durometer make a difference? For the EPDM rings, 70 is all that's shown at oringsusa. Sterling Seal has 50, 60, 70, 80.

Details
https://www.oringsusa.com/catalog/in...?cPath=183_108
-009 QTY: 4
-012 QTY: 2
-014 QTY: 2
-020 QTY: 3
-104 QTY: 3-----

https://oringsusa.com/catalog/index.php/cPath/55
-116 QTY: 3-----

https://oringsusa.com/catalog/index.php/cPath/53
-008 QTY: 2

Jim you're asking the right questions! Unfortunately I do not think I am qualified to answer them...haha.

My guess on Durometer is that it probably does make a difference. I know the original thread starter here took time to measure everything out on the O-ring side of the house so I just selected everything he did. OringsUSA was easy to work with on their newer site as well, they just did not have the Quad-008 one available. Could be worth calling them and see if they have it in stock thought. For the Quad on Sterling Seal I did order the NBR...but your post is making me realized I should order a different material. Good looking out there.

-milly

Jim,

Trying to find the Quad ring or X ring EPDM size 008 has been an uphill battle. I got a quote from aceseal.com to manufacture them. I guess there is an EPDM shortage in the industry right now.

It's like a $15 minimum order so once I get it I can just mail you a few...I'll have some extras. Send me a PM on the side.

-milly

Milly, I never actually rebuilt my pump. I managed to find another one, but that one is now leaking. The links to oringusa.com are dead. Do you have a couple sets of the quad ring and -116 square cut you could sell me?

Just responded to your PM Rex. Unfortunately I do not have any o rings anymore.

milly

I have low mileage '93 and '95+ pumps.

Hello!

I’m back from my sabbatical to Japan and sometime this week I’ll see if I can get the link to those O rings updated or find new sources. I think I have some o rings leftover from when I first did this, but I’ll have to see if they’re the quad ring and -116.

EDIT:
McMaster PN 1170N58 -116 Square cut in Viton

McMaster PN 6540K118 -008 X ring in Viton



On another note, my ABS pump is still leak free.

Matt

I was under the impression that Viton (FKM/FPM) was a poor choice for brake fluid. Ref: https://www.musclecarresearch.com/co...-compatibility

I never found an EPDM option though and ended up with an old ABS pump from ebay. I still have my (much nicer) pump sitting on the floor and would like to rebuild it, but I'm really nervous about using anything but EPDM - and I just can't find these o-rings.

Duh. You’re right. I even discuss this on page one. Hah. Let me try to find another source. Sorry about that.

Matt

I spoke to a couple of places and I was told the best way to do this would be to contact a gasket house and have them stamp the square rings out of a sheet. Also, square rings and x-rings are considered interchangeable although x-rings are technically slightly better sealing. So, 116 and 008 EPDM square rings from a gasket maker. The hunt continues. Will update.

Starting to get responses. Here's the first from O-Rings USA:

"Q-008--- we no longer have a supplier for this profile in EPDM
TS33-116 EPDM----- 50 @ $2.55 ea, 100 @ $1.30 ea-- these are quantity sensitive in regards to pricing-- lead time is 16 weeks- NCNR"

I'm not opposed to the minimum order; I'd pay that to have my unit rebuilt. They ignored my inquiry about a regular square cut ring in 008 though. I don't see the point of ordering the 116 unless I can get the 008 as well. I think the next step is to inquire with gasket makers. Apparently some of them are capable of stamping out what we need from sheets, assuming it has the right thickness.

Ok, I have had the best luck at Global O-Ring which has MOST of the seals in stock and only a $5.00 minimum online order, which is better than the O-Ring Store's $25 minimum. The actually have 008 in square-ring EPDM, which is a direct substitute for the 008 x-ring. What they Don't have is the 116 square cut ring. Still looking.

• E70009 | Global O-Ring and Seal — https://www.globaloring.com/product/e70009/
• E70012 | Global O-Ring and Seal — https://www.globaloring.com/product/e70012/
  
• E70014 | Global O-Ring and Seal — https://www.globaloring.com/product/e70014/
  
• E70020 | Global O-Ring and Seal — https://www.globaloring.com/product/e70020/
  
• E70104 | Global O-Ring and Seal — https://www.globaloring.com/product/e70104/
  
• SE70008 | Global O-Ring and Seal — https://www.globaloring.com/product/se70008/ which is a substitute for (not in stock): QE70008 | Global O-Ring and Seal — https://www.globaloring.com/product/qe70008/
  

Been turned down almost everywhere. No one has the epdm sheet in the thickness we’d need.

Starting to feel like o-ring USA’s effectively $150 order to produce might be the only way to go. What’s stopping me right now is the 16+ week timeline. I’d really like to have my car together sooner.