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914World.com _ 914World Garage _ just another stupid question...
Posted by: Dr. Roger Feb 20 2006, 06:40 PM
is it necessary to "bleed" the proportioning valve?
if so, i guess you just do the right rear, left rear, then prop valve?
thanx guys,
roger
Posted by: r_towle Feb 20 2006, 06:49 PM
yah cant bleed it.
What you need to do is push the air through it and get it out at the calipers...
It needs about 750 psi to get through the valve...(I think) so here is what I do.
bleed each corner in the correct sequence RR, LR, RF, LF
do that twice. Then once you have pedal, push really hard on the pedal for one to two minutes...you will feel each bubble push through the valve...one you have done that, do the calipers again...
You might need to do this whole thing twice to get the bubbles out...
Rich
Posted by: Dr. Roger Feb 21 2006, 09:49 AM
| QUOTE (r_towle @ Feb 20 2006, 05:49 PM) |
| yah cant bleed it. What you need to do is push the air through it and get it out at the calipers... It needs about 750 psi to get through the valve...(I think) so here is what I do. bleed each corner in the correct sequence RR, LR, RF, LF do that twice. Then once you have pedal, push really hard on the pedal for one to two minutes...you will feel each bubble push through the valve...one you have done that, do the calipers again... You might need to do this whole thing twice to get the bubbles out... Rich |
OK guys, if no one's stepping in to say any different, I'm going for it.
I just want the hydraulic system COMPLETELY free of air.
Thanks again to the 914world.com non-member brain trust.
Posted by: Eric_Shea Feb 21 2006, 10:05 AM
Yeah... I'd say go for that. There's been a lot of talk about bleeding the P-Valve, and while it can be a trickey element in the system, I think the buddy approach or Rich's push and hold theory is the best way to go.
The Buddy approach says 'push 3-4 times hard on the pedal and then push very hard, aggressively as you open the bleeder.'
Another simplified approach is: 'Bleed the system as described (RR, LR, RF, LF) then take it out for a spin on the twisties. Make sure your venting clearance is set properly. You may have a little travel in the pedal but... you'll still have good working brakes. Do a few panic stops (once your new pads have set in) on a 'secluded' section of road. You don't want to scare neighbors or get rear ended. Take it back in and re-bleed. Start with just the rears in sequence. That may be all you need.
Basically, all are methods to force the trapped air out of the p-valve.
Posted by: rmital Feb 21 2006, 10:15 AM
| QUOTE (Eric_Shea @ Feb 21 2006, 08:05 AM) |
| methods to force the trapped air out of the p-valve. |
I thought it was just me facing this challange....that friggen'
pvalve
Posted by: Dr. Roger Feb 21 2006, 10:16 AM
thanks eric and rich.
on a side note, i noticed there are two adjusters on each rear caliper.
an inner and an outer.
i see that the outer has a lock nut on the adjuster but can/should anything be done on the inner adjuster???? or just tighten it and call it good?
Posted by: pete-stevers Feb 21 2006, 10:20 AM
certainly doesn't qualify as a "dumb question" thread.....
Posted by: Eric_Shea Feb 21 2006, 10:24 AM
| QUOTE |
| i see that the outer has a lock nut on the adjuster but can/should anything be done on the inner adjuster???? or just tighten it and call it good? |
They 'both' need to be adjusted properly. There's no set-it-and-forget-it back there.
Adjust both to .004... let me know if you need details on the procedure
Posted by: Dr. Roger Feb 21 2006, 10:27 AM
| QUOTE (Eric_Shea @ Feb 21 2006, 09:24 AM) | ||
They 'both' need to be adjusted properly. There's no set-it-and-forget-it back there. Adjust both to .004... let me know if you need details on the procedure |
eric,
i get how to do the outer, i think.... =-))
on the inner there is no lock nut... THAT, I don't get...
i'm sure there's a procedure already created here... soemwhere...
Posted by: Eric_Shea Feb 21 2006, 10:42 AM
| QUOTE |
| I thought it was just me facing this challange....that friggen' pvalve |
Ray, are you lisenced? If so, have Sal let you take it for a week and then come back for a final bleed of the rears.
Posted by: rmital Feb 21 2006, 10:55 AM
| QUOTE (Eric_Shea @ Feb 21 2006, 08:42 AM) | ||
Ray, are you lisenced? If so, have Sal let you take it for a week and then come back for a final bleed of the rears. |
That's the plan...I'm waiting to get an Aux. Air Regulator...install that, then I'm outa there.
Leo and I will then work on the brakes from then on....
Posted by: Eric_Shea Feb 21 2006, 10:55 AM
Roger...
The inner has a cap that will strip when you try to remove it 
Readers Digest:
1. Take your handbrake cable off.
2. Go through the hole in the trailing arm with a long extension and a 4mm hex socket.
3. 'Attempt' to remove the cap. (pray, swear, etc.)
3a. Remove the caliper to spin the cap off with a cold chisel
3b. Your prayers were answered and the cap came off, leave the caliper on and begin the adjusting process.
4. Use the same 4mm to run the 'gear' inside. Clockwise will push the piston 'out' toward the caliper (the adjuster is the cut the same as the front or a normal screw but, because it's gear driven everything on the inner adjuster is backward)
5. Set the clearance to .004. If you don't have a gauge then a business card should suffice.
6. Buy a pair of 10mm caps from PP and 'do not' replace the 4mm hex cap. there is simply not enough surface area in the 4mm hex to overcome the rusted thread engagement of the bore.
7. Repeat on the other side.
Fronts, back off the 13mm nut and adjust as normal with a 4mm hex. Counter closckwise will push the piston toward the pad.
Posted by: Dr. Roger Feb 21 2006, 11:01 AM
| QUOTE (Eric_Shea @ Feb 21 2006, 09:55 AM) |
| Roger... The inner has a cap that will strip when you try to remove it Readers Digest: 1. Take your handbrake cable off. 2. Go through the hole in the trailing arm with a long extension and a 4mm hex socket. 3. 'Attempt' to remove the cap. (pray, swear, etc.) 3a. Remove the caliper to spin the cap off with a cold chisel 3b. Your prayers were answered and the cap came off, leave the caliper on and begin the adjusting process. 4. Use the same 4mm to run the 'gear' inside. Clockwise will push the piston 'out' toward the caliper (the adjuster is the cut the same as the front or a normal screw but, because it's gear driven everything on the inner adjuster is backward) 5. Set the clearance to .004. If you don't have a gauge then a business card should suffice. 6. Buy a pair of 10mm caps from PP and 'do not' replace the 4mm hex cap. there is simply not enough surface area in the 4mm hex to overcome the rusted thread engagement of the bore. 7. Repeat on the other side. Fronts, back off the 13mm nut and adjust as normal with a 4mm hex. Counter closckwise will push the piston toward the pad. |
eric, i didn't see a lock nut for the inner adjusters. is there supposed to be one there???
(i may be missing them as these calipers are the "spaced" ones i got from mar7ck)
Posted by: Eric_Shea Feb 21 2006, 11:05 AM
no... there's a gear in that bore, once you get the cap off.
I should say 'there's supposed to be a gear in that bore'. We no longer ship calipers with the gear because too many were sent to us w/o gears. There came a time when I was down to 2 gears and 40 cores.
No lock nut.
Posted by: Dr. Roger Feb 21 2006, 11:11 AM
| QUOTE (Eric_Shea @ Feb 21 2006, 10:05 AM) |
| no... there's a gear in that bore, once you get the cap off. I should say 'there's supposed to be a gear in that bore'. We no longer ship calipers with the gear because too many were sent to us w/o gears. There came a time when I was down to 2 gears and 40 cores. No lock nut. |
Thanks!
I thought I was trippin' , yo.
Posted by: MattR Feb 21 2006, 12:04 PM
When I first read the title, I thought it said "bleed a prototipo"
my steering wheel doesnt bleed
Posted by: Aaron Cox Feb 21 2006, 12:09 PM
| QUOTE (MattR @ Feb 21 2006, 11:04 AM) |
| When I first read the title, I thought it said "bleed a prototipo" my steering wheel doesnt bleed |
rofl - same here
Posted by: Eric_Shea Feb 21 2006, 12:14 PM
| QUOTE |
| I thought I was trippin' , yo. |
You and the rest of da boys. I'd expect it from a Dead head
but Aaron and Matt... 
Drop the Mr. Natural!
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