How To: Replace Shuttle Valve Seals
How To: Replace Shuttle Valve Seals
#2
07-01-2011, 10:20 PM
Pro Wrench
Again, great pictures! I should have taken pictures when I replaced my shuttle valve seals the other weekend, along with shuttle valve switch, and your option "B" repair.
When I replaced my seals, I had no instructions to follow, so I had to make it up as I went. I didn't perform your step 3, 4, and 5. I was able to use a straight needle nose pliers, grasp the end of the valve, and pull the entire plunger assembly out: spacer, circlip and all. Once out, I replaced the seal, reassembled the spacer and clip, and slid the entire assembly back into the modulator.
If you use the Falconworks kit, they send you four circlips. The original plungers had one clip per, but Falconworks advises using two of their thinner clips per plunger. IIRC, the plungers , or spacers are different size side to side, so do one at a time.
Josh, even had I taken pictures, they wouldn't have turned out nearly as well as yours!
When I replaced my seals, I had no instructions to follow, so I had to make it up as I went. I didn't perform your step 3, 4, and 5. I was able to use a straight needle nose pliers, grasp the end of the valve, and pull the entire plunger assembly out: spacer, circlip and all. Once out, I replaced the seal, reassembled the spacer and clip, and slid the entire assembly back into the modulator.
If you use the Falconworks kit, they send you four circlips. The original plungers had one clip per, but Falconworks advises using two of their thinner clips per plunger. IIRC, the plungers , or spacers are different size side to side, so do one at a time.
Josh, even had I taken pictures, they wouldn't have turned out nearly as well as yours!
Last edited by lordmorpheus; 07-01-2011 at 10:33 PM. Reason: spelling
#3
07-01-2011, 10:38 PM
Again, great pictures! I should have taken pictures when I replaced my shuttle valve seals the other weekend, along with shuttle valve switch, and your option "B" repair.
When I replaced my seals, I had no instructions to follow, so I had to make it up as I went. I didn't perform your step 3, 4, and 5. I was able to use a straight needle nose pliers, grasp the end of the valve, and pull the entire plunger assembly out: spacer, circlip and all. Once out, I replaced the seal, reassembled the spacer and clip, and slid the entire assembly back into the modulator.
If you use the Falconworks kit, they send you four circlips. The original plungers had one clip per, but Falconworks advises using two of their thinner clips per plunger. IIRC, the plungers , or spacers are different size side to side, so do one at a time.
Josh, even had I taken pictures, they wouldn't have turned out nearly as well as yours!
When I replaced my seals, I had no instructions to follow, so I had to make it up as I went. I didn't perform your step 3, 4, and 5. I was able to use a straight needle nose pliers, grasp the end of the valve, and pull the entire plunger assembly out: spacer, circlip and all. Once out, I replaced the seal, reassembled the spacer and clip, and slid the entire assembly back into the modulator.
If you use the Falconworks kit, they send you four circlips. The original plungers had one clip per, but Falconworks advises using two of their thinner clips per plunger. IIRC, the plungers , or spacers are different size side to side, so do one at a time.
Josh, even had I taken pictures, they wouldn't have turned out nearly as well as yours!
LOL Im sure they would have been equally helpful!
Check the instructions again (#1 and right before # 3... I just updated with your info)
#4
07-01-2011, 11:13 PM
Pro Wrench
Now I really wish I had taken pictures, to illustrate how to pull the plunger out, without having to remove the circlip first. Basically, you use a pair of good needle-nose pliers (that actually still have grippy serrations at the tip) and grab the small end of the plunger, just above the circlip, and pull straight out. You can then remove the circlip, spacer, and spring, replace the seal, reassemble, and slide back into the modulator.
Bleeding the modulator after reassembly: I didn't have a Testbook to bleed the modulator, but after I reconnected the brake lines, I filled the master cylinder to the maximum, and left off the cap. I then started gravity bleeding with the right rear. Once the fluid ran clear (no bubbles) from the bleeder at the wheel, I started the engine with my foot on the brake pedal. (I remembered that on a normal start, I could hear the modulator do something as the engine started (just a noise as the pedal sank). With the engine running, I pumped the pedal a few times, let it gravity bleed for about 10 more minutes, closed that bleeder and moved on to the next. I repeated the same process with the left rear, right front, and left front.
After I had bled each wheel, I engaged the HDC in low range and made a few laps around the block, accelerating and then letting the HDC slow it down, to make sure all air bubbles were out of the modulator, after the ABS had been activated repeatedly.
I was expecting to have to bleed it again, but after a few laps around the block, the brake pedal felt perfect.
I don't know if this bleed procedure is correct, but it worked for me.
Bleeding the modulator after reassembly: I didn't have a Testbook to bleed the modulator, but after I reconnected the brake lines, I filled the master cylinder to the maximum, and left off the cap. I then started gravity bleeding with the right rear. Once the fluid ran clear (no bubbles) from the bleeder at the wheel, I started the engine with my foot on the brake pedal. (I remembered that on a normal start, I could hear the modulator do something as the engine started (just a noise as the pedal sank). With the engine running, I pumped the pedal a few times, let it gravity bleed for about 10 more minutes, closed that bleeder and moved on to the next. I repeated the same process with the left rear, right front, and left front.
After I had bled each wheel, I engaged the HDC in low range and made a few laps around the block, accelerating and then letting the HDC slow it down, to make sure all air bubbles were out of the modulator, after the ABS had been activated repeatedly.
I was expecting to have to bleed it again, but after a few laps around the block, the brake pedal felt perfect.
I don't know if this bleed procedure is correct, but it worked for me.
Last edited by lordmorpheus; 07-01-2011 at 11:30 PM.
#6
07-21-2011, 08:03 PM
TReK
Dear god, don't you guys listen to us LR techs, the easiest way to bleed any modulator is to bleed it at the modulator. Not the brakes. just fill the reservoir then have an assistant pump the brakes five times and hold. open the first line on top then open all five of the lines and then tighten up and pump five more times then open them again. this time starting with the second one on the top and then open all five lines, then pump five more times, open the third one, pump five times and then the fourth one on top and the all five and fill it back up. that will get the air out without using testbook. In fact this way works for any modulator on any vehicle except for older P38 and RRC.
#7
07-21-2011, 08:15 PM
Pro Wrench
Rovin4life: That bleed method would have been faster than my method, IF I had someone to help me. Instead, it took me probably the same length of actual work time; opening the bleeders; then letting gravity do the rest while I took a beer break. Granted, by the time all of the wheels had been bled, I probably shouldn't have been driving due to the beer breaks, but low range with HDC engaged prevented excessive speed.
#8
07-22-2011, 08:53 AM
Nice writeup. I have always wanted to do a blog similar to yours and faithfully record all my auto repairs, but alas I have not done it. Thank goodness somebody is on point around here.
One note though, if the switches aren't bad the seal kit alone can be purchased from Falcon for $36.43 + shipping and potentially save you about $90. Link is here:
Discovery shuttle valve seals & new style reaining clips
One note though, if the switches aren't bad the seal kit alone can be purchased from Falcon for $36.43 + shipping and potentially save you about $90. Link is here:
Discovery shuttle valve seals & new style reaining clips
#9
09-21-2016, 08:53 PM
Dear god, don't you guys listen to us LR techs, the easiest way to bleed any modulator is to bleed it at the modulator. Not the brakes. just fill the reservoir then have an assistant pump the brakes five times and hold. open the first line on top then open all five of the lines and then tighten up and pump five more times then open them again. this time starting with the second one on the top and then open all five lines, then pump five more times, open the third one, pump five times and then the fourth one on top and the all five and fill it back up. that will get the air out without using testbook. In fact this way works for any modulator on any vehicle except for older P38 and RRC.
#10
09-22-2016, 03:01 AM
It's pretty unclear, but if I had to hazard a guess, I'd say this:
* There are six lines into the modulator, and I think the one on the side toward the firewall comes from the master cylinder, so I think the idea is that this one stays in (delivering brake fluid to the modulator when you hit the pedal).
* I think the general idea is that you loosen each of the four lines on top and pump the brakes until fluid comes out. Between each of these loosenings, you do a cycle where you loosen all five of them and pump until fluid oozes out. That should get the air out of the modulator.
I guess this would work, but it'd be messy for sure.
* There are six lines into the modulator, and I think the one on the side toward the firewall comes from the master cylinder, so I think the idea is that this one stays in (delivering brake fluid to the modulator when you hit the pedal).
* I think the general idea is that you loosen each of the four lines on top and pump the brakes until fluid comes out. Between each of these loosenings, you do a cycle where you loosen all five of them and pump until fluid oozes out. That should get the air out of the modulator.
I guess this would work, but it'd be messy for sure.