Back again after a diff swap with brake troubles.
#21
Hi Hydro
A Blocked Valve in the ABS is usually the result of either not renewing Brake Fluid on a regular Basis.
Or Levering the Brake Pads back into the Calipers, when for instance replacing the Brake Pads, without having the Bleed Nipple open (This is the Kiss of Death on an XJS)
As this sends Brake Fluid the wrong way up the System, where the Microscopic hole in a Valve (or Valves) can get Blocked up with a Microscopic piece of 'Crud'
Hence the Sharp Pull from one side to the other.
Or it could be a Broken Wire in the ABS Valve Block which can produce exactly the same result.
Or a malfunctioning Wheel Speed Sensor.
A Blocked Valve in the ABS is usually the result of either not renewing Brake Fluid on a regular Basis.
Or Levering the Brake Pads back into the Calipers, when for instance replacing the Brake Pads, without having the Bleed Nipple open (This is the Kiss of Death on an XJS)
As this sends Brake Fluid the wrong way up the System, where the Microscopic hole in a Valve (or Valves) can get Blocked up with a Microscopic piece of 'Crud'
Hence the Sharp Pull from one side to the other.
Or it could be a Broken Wire in the ABS Valve Block which can produce exactly the same result.
Or a malfunctioning Wheel Speed Sensor.
On the plus, the ABS is functional, I tested it after all the work as part of the process. That leads me to believe the problem is not electrical. Also, common sense tells me that if it was physically blocked in the valve port, the pull would be constant, right? The car brakes perfectly straight after the momentary pull. It seems more like there's a delay in the pressure to that wheel... Which I guess does sound ABS related. Ugh, here I was thinking I got away without touching that snake pit.
The following users liked this post:
orangeblossom (12-08-2016)
#22
Hi Hydro
Things may not be quite as bad as they seem, as I am now thinking that you may just have a sticking Brake Pad.@Greg.
If you look at the First Photo, when that pad was New I just took it out of the Box and Slid it in but when I went to replace it, I needed a FBH and
a Chisel to get it out and the same on the other side.
Probably took a Couple of hours to do.
But what I have picked up on, is that depending where the Brake Pad was Manufactured, there can be a Slight variance in the fit.
As I noticed when I recently fitted New Pads and Calipers.
Although the New Brake Pads went in ok, I did have to give them a little bit of a Tap, which meant that they might possibly jam in the Caliper, or
at least not move as smoothly as they should.
So I took them out and Sanded a bit off the Top and Bottom edges, until they slipped in just right.
If your New Pads are a tight fit, then that might also be an easy fix for your 'slight pull problem'
Also a New Fixing Kit works wonders. ebay £10
Don't let that Brake Cleaning Fluid anywhere near the Caliper Piston Rubbers or it could melt them.
The Brake Pad was much too tight in the Calipers, which could lead to it jamming.
Brake Pad was too much of a Tight Fit, so I ground a bit off the Top and Bottom edge, until it slid in perfect.
Keep the Brake Cleaner away from the Caliper Piston Rubbers.
After Grinding a bit off the Top and Bottom edges of the Brake Pads to avoid them 'Jamming' they were a much better fit.
A New Brake Pad Fixing Kit also works Wonders.
Things may not be quite as bad as they seem, as I am now thinking that you may just have a sticking Brake Pad.@Greg.
If you look at the First Photo, when that pad was New I just took it out of the Box and Slid it in but when I went to replace it, I needed a FBH and
a Chisel to get it out and the same on the other side.
Probably took a Couple of hours to do.
But what I have picked up on, is that depending where the Brake Pad was Manufactured, there can be a Slight variance in the fit.
As I noticed when I recently fitted New Pads and Calipers.
Although the New Brake Pads went in ok, I did have to give them a little bit of a Tap, which meant that they might possibly jam in the Caliper, or
at least not move as smoothly as they should.
So I took them out and Sanded a bit off the Top and Bottom edges, until they slipped in just right.
If your New Pads are a tight fit, then that might also be an easy fix for your 'slight pull problem'
Also a New Fixing Kit works wonders. ebay £10
Don't let that Brake Cleaning Fluid anywhere near the Caliper Piston Rubbers or it could melt them.
The Brake Pad was much too tight in the Calipers, which could lead to it jamming.
Brake Pad was too much of a Tight Fit, so I ground a bit off the Top and Bottom edge, until it slid in perfect.
Keep the Brake Cleaner away from the Caliper Piston Rubbers.
After Grinding a bit off the Top and Bottom edges of the Brake Pads to avoid them 'Jamming' they were a much better fit.
A New Brake Pad Fixing Kit also works Wonders.
Last edited by orangeblossom; 12-08-2016 at 05:35 AM.
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Greg in France (12-08-2016)