| Author |
Message |
    
cooper
| | Posted on Monday, September 30, 2002 - 01:00 am: | 
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Anyone, I just changed out my rotors to some drilled and slotted types w/ Kevlar pads and wondering how long does this set-up take to break in? Will the brakes feel mushy for a while? this is for my 96 D1. |
Mark Smith (Msmith)
| | Posted on Monday, September 30, 2002 - 01:03 am: |
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Did you bleed the system after the change? |
cooper
| | Posted on Monday, September 30, 2002 - 01:06 am: |
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I didn't only because all I did was push the caliper pistons all the way back into the caliper body, that shouldn't change the pressure in the system should it? |
Markd1x2 (Markd1x2)
| | Posted on Monday, September 30, 2002 - 06:23 am: |
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Did you follow the guidelines for temporarily lowering the level of brake fluid in the reservoir before compressing the pistons?
Did you monitor the reservoir fluid level during your rotors change ?
You may have back-forced out some of the fluid when pushing the pistons. Check the reservoir. |
Bill Bettridge (Billb)
| | Posted on Monday, September 30, 2002 - 08:11 am: |
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You shouldn't force fluid back through the system - especially an ABS system. Best way is to open the bleed screw to compress the pistons.
Anyway - start with a full system bleed and then see what happens.
Another thing is the Kevlar pads probably don't work to well cold (I went with the drilled rotors, but used standard pads and had no problems)
Bill |
hendrik
| | Posted on Monday, September 30, 2002 - 02:57 pm: |
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I dont know about the ABS systems, but what harm could the "forcing the pistons back" do to the standard Land Rover brake systems. All I can see is that there is danger to "overfill" the reservoir and no chance for air to get into the lines. See, when you release the brakes the piston will be pulled back into the caliper a little bit by the rubber ring seal so basically doing the same as Cooper, but only to lesser amount. Air in the system makes a soft pedal, I would second Bill with the pad assesment. |
Bill Bettridge (Billb)
| | Posted on Monday, September 30, 2002 - 03:42 pm: |
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Hendrik - the theory that I here tossed around about ABS systems is that is it is not a good thing to force any fluid which MAY contain contaminate particles backwards through the ABS valves. I know in other fluid power systems that essentially have a 1-way flow all the time, "crap" (for lack of a better term) can accumlate in various junctions/fittings/unions/etc and then be dislodged by backwards flow of fluid through the system. Generally this is no big deal, until you are dealing with the ABS valves.
I don't know this for sure about ABS, but do have a few folks that I trust on these issues and do it for a living and that is their little gem of wisdom.
FWIW
Bill |
Paul T. Schram (Paulschram)
| | Posted on Monday, September 30, 2002 - 03:58 pm: |
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Bill:
So that's why I haven't noticed any problems with just pushing the pads back in-the Anti-Lock light has been on for so long, I think I'd miss it if it were to be extinguished!
Somewhat more seriously, I think if you were worried about introducing something into your brake fluid system from without, there might be a bigger problem.
Granted,the mild steel pistons do get pretty well torn up in the salt around these parts, I wonder just how much of that stuff would get into one's fluid side of the brakes? I'm not sure that I'm not more worried about the condition of the inside of my brake hydraulic system. Judging from the color of the fluid in the reservoir, I should be bleeding (read changing brake fluid) this evening after work.
You are absolutely right about the bleeding and the Kevlar pads. The bleeding is a messy job-don't wear those nifty Mechanix gloves, the dye will run with brake fluid and stain your hands (and everything in the washer). Kevlar pads sound sexy, but probably don't do much on vehicles like ours that won't go fast enough to heat the Kevalar enough unless dropped from a plane and then, your brake pads won't be of that much benefit!
I found a reason why I don't like the teflon power steering hose with the stainless braid around it. I was looking for the source of •••••• fluid... Looked up at the ps line and the little bit of light that passes through the braid and the tube makes it look like it's leaking, but when you wipe it down, it's clean. The •••••• cooler lines are seeping.:-) I got about six feet of LOLA+ nitrile tubing to replace all of my cooler lines-at least the plastic parts.
Paul |
Bill Bettridge (Billb)
| | Posted on Monday, September 30, 2002 - 04:31 pm: |
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I guess each to their own about the theory of pushing fluid backwards through the system - I won't fight that battle here 
After I invested in the power bleeder - I don't mind the job at all (even on the wifes ABS RRC) - hell, I even volunteer to do it for friends!
LOLA is good hose - even resists brake fluid! Just don't make the mistake that I've seen done very often and put a clamp on top of the push-on fitting barb (if you're using the push-on fittings the hose was designed for that is) - you'll cut right through the tube. The push-on fitting alone will do the trick up to the WP of the hose. Not that you would, but I've seen it done all to often and people wonder why it fails!
Have fun replumbing
Bill |
Paul T. Schram (Paulschram)
| | Posted on Monday, September 30, 2002 - 04:42 pm: |
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Bill:
Thank you-I was intending to put a hose clamp behind the existing hose barb. Are you referring to the barbs that will be exposed when I cut the crimped collar off of the existing hose? Given your background, I will defer to your experience. Should I cut the barbs off and just use the tubing and a clamp? What about compression fittings and a hose barb? I'm worried about busting a hose while wheeling and am carrying a roll of tubing and a box of hose clamps.
What power bleeder do you have? You and Perrone preach the benefits, maybe it's time I bought one. That will render the argument (discussion topic) moot.
Paul |
cooper
| | Posted on Monday, September 30, 2002 - 05:38 pm: |
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I guess I should have thought about the ABS system a little more before the brake swap. I did backflow the system w/o regard to contamination. I did bleed the system however, and I still feel like the brakes just don't grab as well as they should. I wish I had asked about the Kevlar pads bfore the money was spent.. |
SteveSherman
| | Posted on Monday, September 30, 2002 - 05:58 pm: |
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Here's a little something from my racing days...hope it helps.
The first step in preparing the brake system for duty is to "SEASON" the rotors. The most complex task this performs is that of relieving the internal stresses within the material of the rotor. If you've ever poured water into a glass of ice, and noticed the ice cracking, then you've witnessed, first hand, the effects of internal stresses. The rotor casting and cooling processes leave the rotor with internal stresses. The most visible effects are that of burning the machine oils from the surface of the iron and establishing a wear pattern between the pad and rotor. Baer offers on-line instructions for "Seasoning Rotors and Bedding Pads" for street or race applications at www.baer.com/bedding_street or www.baer.com/bedding_race. |
Bill Bettridge (Billb)
| | Posted on Tuesday, October 01, 2002 - 08:52 am: |
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Paul -
1) I've got the Motive powerbleeder and I love the thing (really - I'd bring it to bed if the wife would permit J/K) It makes life so easy (and for such a relatively small price)
2) If you are using the "push-on" style fittings that LOLA was actually designed for - do not use an additional clamp, but if you are reusing the barbs/beads on the stock lines or are using standard barbed fittings (ie: not push-on style) - go ahead and use any clamp you wish (my personal preference is worm gear style which either do not have the slots or that have the slots covered on the underside which keeps the hose cover from extruding through the slots on a standard worm gear)
Good luck
Bill |
muskyman
| | Posted on Tuesday, October 01, 2002 - 10:01 am: |
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I'm with Bill, ABS systems should never be done by compressing the fluid back into the system when you do you force moisture back into the abs pump that can cause the pistons in the abs system to work unevenly causing the ABS to funtion differently at each corner. the most common problem is when one wheel seams to kick in before the others.
a simple $60 vacume pump will help you bleed the system. allways start with the corner farthest from the ABS and work to the closest.
back in my BMW autocrosser we found that not changing the brake fluid would cause uneven pad wear and braking distance increase to the point that you could not threshhold brake from the same braking lines on the track. I could come off the track and know that I needed a full bleed even though the rotors and pads where all new.
as far as "seasoning the rotors" good rotors are heat normalized before the final cut when they are made. you shouldent have to super heat them like guys used to 20 years ago. if you are using cross drilled rotors chances are that they are heat normalized after the drilling process to prevent any cracks from starting at the cross drilled holes. |
Jon Williams (Jonw)
| | Posted on Tuesday, October 01, 2002 - 06:37 pm: |
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..which actually are falling from popularity. CART and Formula-1 teams have been using cross-drilled rotors for some time now, but they're finding that the drilled rotors are prone to cracking and really offer no increase in stopping power when compared to plain slotted rotors.
Not that it makes the people happy who've put those drilled rotors on their Discos, but it's something to consider if you were thinking of buying some. |
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