I am going to replace the shuttle valve on my abs nit. See if it fixes my lights.

Question is I have not seen explicitly if I will have to bleed the brakes if I do not disconnect the lines to the abs unit. Does anyone know?

I have replaced the same unit in a bmw, the entire unit, and did not have to bleed, but the lines enter the top of the unit

Does anyone know definitely?

Thanks

 

There is absolutely no need to disconnect the ABS modulator to fit new shuttle valves. If you read the fix 'sticky' carefully it tells you how to do it. If you disconnect the modulator and it will drain the brake fluid in the primary circuit you are highly unlikely to be able to bleed the air out without either LR Test Book, Nanocom or Hawkeye equipment and procedure. Your brakes will be worse than when you started.

There is lots of info on here, LRF.com (use the search facility) and on the www in Australia etc.

 

If you are going to go to the bother of replacing the shuttle valve, you might as well do the job right at replace the seals as well. They, in fact, are the source of the problem with the three amigos when it relates to a shuttle valve failure.

After awhile (especially 10-15 years) the tiny seals at the bottom of the shuttle valve plungers go bad. They leak brake fluid onto the shuttle valve. We all know how nasty brake fluid is. Well, given time, the brake fluid damages the shuttle valve and you get the three amigos.

Now, you can just replace the shuttle valve but I am willing to bet that, with the seals still leaking, you're looking at redoing the job in the not too distant future. It could be anywhere from a few months to a couple of years but the leak will eventually damage the new shuttle valve in the same way it destroyed the original.

If you're interested, I have a brand new shuttle valve with the replacement seals for sale. It came from Falconworks, the guys who really know this stuff and have saved many people from wasting a lot of needless time and effort in doing this repair. If you're interested let me know. I also have a great modulator that has been tested with a Hawkeye and has no issues whatsoever.
Cheers,
Paul

 

paul,

is absolutely correct to repair the shuttle valve switches without doing the seals is a waste of time and effort, you will be back there again

 

I just listed the kit I had in the classifieds and it sold to Abran in about a minute!!!

 

Thanks for the advice, I forgot about the falcon works kit.

Visually, as opposed to the OEM WEBCO, it appears the only difference is the yellow plastic and the 4 circlips.

What/wear do those seals go? Can they be bought separately? Are they the two round items that appear to be rubber washers?

 

falcon works

 

Yes, you can buy the seals separately from Falconworks. I think they're about $45, granted, an outrageous price but they can't be bought elsewhere. They really are the key to returning the modulator to the way it was when it was new. Without the seals, you're only buying time until the shuttle valve fails again.

Here's the link to the seal kit on their site.

Discovery shuttle valve seals & new style reaining clips

I think the steps for the replacement might be in the stick at the top of this page. I know you get instructions from Falconworks when you buy the parts from them.

 

I ordered the new orings and circlips.

I will have to measure them and find an alternative source for the board. I would bet Granger has them.

 

Good luck, you won't be the first to try.