DI Brakes Just Not Good Enough

[kennith]

Thank you both for clarifying.

I look forward to what RBBailey reports back as the solution. I wish I had more personally to offer on the topic.

There's really nothing else to offer until tests are performed. Hydraulic disc brakes are relatively simple.

We know what the causes can be; it's just a matter of finding out which one is in play, or how many are in play. Typically, when so much is removed and reinstalled, you've got air in the system somewhere, even if you can't imagine how it got in there; but that's not necessarily the case.

Nobody can know what the problem is until that's been fully explored. It's a pain in the ass, but that's an important variable to eliminate.

Cheers,

Kennith

 

[discostew]

Well I really don't think you can fix cars long distance like this. You actually need to lay your hands on stuff to diagnose it and fix it. Maybe you can, but then who really knows if your crackpot theory fixes it, it never gets tested.

 

[fishEH]

I updated my original thread with pictures for the Power Probe.

Power Probe brake bleeder

So I have a Motive power bleeder that I've used on my D1. The cap adapter never fit great, it even leaked a few times. Screwing it on/off was always a pain because there's no swivel. I'm coming up on a brake fluid flush for my 2015 Honda Odyssey and looked for the proper Motive adapter. It was...

discoweb.org

Yep. Cut the hose on the Motive. Install a barbed to female air coupling. Done.
Tooldiscounter.com seemed to have the best price.

 

[kennith]

Well I really don't think you can fix cars long distance like this. You actually need to lay your hands on stuff to diagnose it and fix it. Maybe you can, but then who really knows if your crackpot theory fixes it, it never gets tested.

Remind me never to have my vehicle serviced at your dealership if I ever accidentally walk in.

Cheers,

Kennith

 

[discostew]

What the fuck is wrong with you Kenny?

 

[RBBailey]

That seems like a waste of time and fluid since a ton of air is going to be introduced when you swap lines.

Only need to check to see if any bubbles got sucked back in that I hadn't noticed. So a few pumps on each wheel should do it. I did a lot of bleeding the first time because it was the first time I'd used the Speed Bleeders, and wanted to make sure it was working as I thought; also, the old fluid was pretty bad, so I felt like really cleaning out the pipes.

 

[lilmul]

Hi everyone I have been reading and I have a cpl of questions .
1. Do you not have to change the disco 1 brake master cylinder when you up grade to the defender 110 front brake calipers ? The master cylinder is designed to pump a certain amount of fluid to a measured size piston.
I tried this very up grade and found my d1 master cylinder went right to the floor and I had NO brakes.
Once I pumped the brake peddle once the brake peddle feel was rock solid and the peddle travel only went down about a half to one inch. The brakes did work ok but they were still crappy . My theory was you needed a master cylinder with a larger bore to displace more fluid to compensate for the larger pistons in the front calipers.

2. I have two options to go here . I can install a old RRC brake peddle with a bigger booster and a 110 master cylinder.
I will have to change the peddle assembly because the master cylinder mounting bolts on the d1 are on a angle and can’t be moved to fit the 110 master. If I use a RRC peddle assemble I get the bigger booster and the mounting bolt pattern is same as a early 110 or series peddle tower because the two bolts are mounted in the correct location.

Just a little back story I have changed out all the brake lines (hard and flex) I also changed the d1 master to a new d1 master and had the same problem with the peddle going to the floor. One pump and the brakes were sort of ok.

I have seen someone mention the Wabco power booster being wired into the D1 .
I have a p38 here for parts and would love to know how to hook it up to my d1

My d1 also has all of the old crapy d1 abs sHit removed and I have gone back to the old system .

My axles are 21/22L axles out of a 110 . The truck came with both front and rear Salisbury’s so no abs.

Thoughts I know it was winded sorry

Tony

 

[Tugela]

1. Do you not have to change the disco 1 brake master cylinder when you up grade to the defender 110 front brake calipers ? The master cylinder is designed to pump a certain amount of fluid to a measured size piston.
I tried this very up grade and found my d1 master cylinder went right to the floor and I had NO brakes.
Once I pumped the brake peddle once the brake peddle feel was rock solid and the peddle travel only went down about a half to one inch. The brakes did work ok but they were still crappy . My theory was you needed a master cylinder with a larger bore to displace more fluid to compensate for the larger pistons in the front calipers.

I installed D110 front calipers on two different D1s without changing the master cylinder. The result in both cases was a softer pedal feel and increased stopping power. From what you describe it sounds like you have other issues hindering your brake performance.

 

[p m]

I installed D110 front calipers on two different D1s without changing the master cylinder. The result in both cases was a softer pedal feel and increased stopping power. From what you describe it sounds like you have other issues hindering your brake performance.

What he said.

 

[Icannap1]

I also did the Defender vented upgrade 3 weeks ago kept the D1 MC and formed the original hard lines to fit the new defender calipers they fit perfect the key is to form the hard lines while still attached to the old D1 calipers. The benefit of installing the whole new defender system first then doing the hard lines last is that there is still some pressure in the lines so when you form them they don't collapse when bending the lines you can get them as close as possible to where the Defender has the port then just unscrew the fitting and immediately install it on the new caliper so you don't loose to much fluid and let to much air in to the line. I had to bleed the fronts 4 times to build up pressure then do a complete bleeding on all four a total of 8 times from farthest to closest to the D1 MC. the end result t works. the next day I for time by having my son pump the brakes a total of 6 times to each bleed form farthest to closest the only difference is that I had him count it out so could close the valve as he was pressing the last pump number 6 that made a world of difference was to close it while the last pump was being done vs. closing the valve once the last press was held in position. Keep bleeding the system till you get the results your happy with.

 

[hks3sgte]

My ‘87 RRC has a stiff pedal but can lock up the tires.

My old ‘95 Disco couldn’t lock them up even with ABS disabled.

 

[RBBailey]

OK, finally getting to next step in this process. Next attempt: I'm going to swap in some good pads. When I bought the car, the guy was flipping it, trying to make a buck. He probably picked it up for $500. Either way, he had done an oil change, new battery, and he said he did the brakes. So I inspected the brakes, and found that they did in fact look like new rotors and pads. Well, two years on, the front pads really show very little wear at all.

As someone mentioned here, this could be a big part of the issue. I suspect the guy I bought it from just went to Autozone and ordered up the cheapest set of brakes he could, just to be able to say they don't squeal or grind, and look, they're new! So I want the best pads I can find.

I'm looking at PN SFP500220, is this correct? 1998 Disco I LSE.

 

[fishEH]

Cheap pads have never been an issue for me. I've bought a bunch of $8 pads for a D1 and D90 and they've stopped my trucks as well as more expensive pads.
Seized calipers and the crappy clip system in the rear have always been the biggest issue for me.

 

[RBBailey]

Thing is, I think a seized caliper would result in uneven braking, uneven wear, and maybe even a stiffer than normal pedal. Maybe I'm wrong?

Rovers North only has the pads without sensors. I've always been really bad at figuring out which part I need just by the numbers, especially when you have a whole list of them that all say they fit the same thing, different numbers, order the one I think I want, wrong one when I get it.......

 

[fishEH]

I've had 5 D1's from 94 to 98, SD, SE7, and LE trim levels. None of them have used pads with sensors. I'm not sure what years/trims actually used pad sensors, if any??

 

[terryjm1]

Think the pads are made to fit a number of different vehicles. I have a Triumph TR8 that I ordered pads for and they came with sensors. No TR8 ever made had pad wear sensors. Although, lol, I considered creating a circuit to tie them into the binnacle brake warning light.

 

[discostew]

I've had 5 D1's from 94 to 98, SD, SE7, and LE trim levels. None of them have used pads with sensors. I'm not sure what years/trims actually used pad sensors, if any??

Range Rover Classic uses the sensor. I've bought aftermarket pads and I just cut those wires off.

Thing is, I think a seized caliper would result in uneven braking, uneven wear, and maybe even a stiffer than normal pedal. Maybe I'm wrong?

The pistons get stuck in. When the pads are worn the surface of the piston is exposed, then someone gets them back in the caliper with a 3 foot pry bar so they can fit the new pads. So they might be ok for a little while but all that rust that got jammed back into the bore with the piston gets to work doing whatever rust does when nobody's watching.
Usually when that happens you hear squeel when your off the pedal at like 30 mph.

The only other thing I think could be going on is one of your proportioning valves being slammed to one side. You know when that happened because you will have really poor flow of brake fluid when bleeding.
You did bleed from the lines on the master and the lines on the modulator right?

 

[RBBailey]

Range Rover Classic uses the sensor. I've bought aftermarket pads and I just cut those wires off.


The pistons get stuck in. When the pads are worn the surface of the piston is exposed, then someone gets them back in the caliper with a 3 foot pry bar so they can fit the new pads. So they might be ok for a little while but all that rust that got jammed back into the bore with the piston gets to work doing whatever rust does when nobody's watching.
Usually when that happens you hear squeel when your off the pedal at like 30 mph.

The only other thing I think could be going on is one of your proportioning valves being slammed to one side. You know when that happened because you will have really poor flow of brake fluid when bleeding.
You did bleed from the lines on the master and the lines on the modulator right?

Ah! Yes, I knew this about the RRC vs. DI pads! I wish the vendors would say so on the web sites, I completely forgot about that. Thanks.

About the pistons. I think you are confirming what I was thinking, that it isn't pistons due to lack of some particular symptoms. Could be, and I'll check when I put pads in.

Bleeding went well, but I wouldn't be able to tell you if the flow was particularly slow, or.... Just haven't done it enough times to know if it seemed odd.

 

[RBBailey]

BTW, does anyone know if this means one set.... as in one wheel, or one axle?

SFP000280-FERODO Brake Pad Set Rear Def 110-Land Rover Parts Direct

 

[fishEH]

Those are 110 rear pads. So unless you changed out your D1 rear calipers to D110 calipers that use pins and cotter pins, the ones you linked are a no-go. The ones you linked are the same as these: https://www.roverparts.com/Parts/SFP000280

BTW, does anyone know if this means one set.... as in one wheel, or one axle?

SFP000280-FERODO Brake Pad Set Rear Def 110-Land Rover Parts Direct