So this is one that has been touched on a million times but i need to find a resolve. Everyone's resolve is "its a Disco, they all suck" First of all the car I am talking about is @annabellerover 1996 D1. The brakes are just weak. No stopping power. it has normal pedal feel and travel. I have replaced the Master twice, Braided steal brake lines, willwood prop valve, abs modulator has been deleted, front vented disc upgrade, all pads and rotors have been replaced. I have 2 identical discos and the other one stops absolutely perfect. Nothing I have done has made a lick of difference so I am asking for suggestions.
Weak Brakes D1
- Thread starter special ed
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@LRDONE Same Pads i use on everything in the shop, Textar pads and High carbon coated rotors. Calipers are free and good, pads wear normal. Ive been chasing this for years.
@lunchbox I would expect a hard pedal if there was a leak or if the booster had an issue. I am almost ready just to change it just to see if it makes a difference. Its pretty much the only thing i have not changed but this just does not seem like a booster issue, thats why im stumped.
@lunchbox I would expect a hard pedal if there was a leak or if the booster had an issue. I am almost ready just to change it just to see if it makes a difference. Its pretty much the only thing i have not changed but this just does not seem like a booster issue, thats why im stumped.
Do you think the caliper pistons are ok? I think the biggest cause of what your describing is the pistons being all shitted up and not moving freely. I've seen some so rusted that I wasn't able to get the piston out. You can tell when thats happening because the rotor will look like a car that hasn't been driven in a long time even though it's driven every day.
Yeah this could be too. The way you tell if your brake booster is working is apply the brakes hard a couple times with the engine off. Then while holding the pedal down start the engine. When the vacuum hits the booster it should pull the pedal down.
I double checked the booster today, changed the oring behind the master and checked the adjustment of the rod inside. its all good and the booster is working properly. no vacuum leaks. It is a california/colorado car so no rust and the brake pads and rotors are wearing evenly and normal. Master was changed actually 3 times and i now have a trw in there. I think next thing to do is rebuild the calipers. Ill try that next. Literally everything has been replaced so best guess is the calipers binding.
You can get the pistons and seals. I’ve always reused the small seal that sits between the halves when the caliper is separated.
I’ve fixed lots of them like this
You can try unbolting the calipers and watch how the pistons move while someone pushes the brake pedal.
Make sure to put a piece of wood in between the pads or pistons so they can’t move too far out.
Trying front calipers first. My vendors were not cheap so i did a little googogling. Found one on rock Auto for 34$ the other on Amazon for a bit more. I'm going to rebuild the take offs with some stainless steel pistons and put them back on if this works. If not ill try the rears next and report back. I was thinking last brake job I did the rears. They were not that old but thought it might be the adjustment on the Wilwood prop valve. Now thinking maybe the front calipers are stuck.
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If you have a chance, I would like to see a pic of your ABS delete with the Willwood prop valve. Going to do that while I have motor and trans out. My third D1 and I have never had one with the ABS functional. I've wanted to delete the module since my first one. I am going to have air filter from snorkel pass through where the module sits.
My last one I had same issue with brakes, even after the Def brake upgrade in front and disc conversion on rear Salisbury. The upgrades helped but never solved it. My first stopped on a dime, even with the 305/70/16's on it. My current one still bone stock stops really well, so I guess just luck of draw. They were all 97's but the last one was pre AEL, first and current ones AEL.
My last one I had same issue with brakes, even after the Def brake upgrade in front and disc conversion on rear Salisbury. The upgrades helped but never solved it. My first stopped on a dime, even with the 305/70/16's on it. My current one still bone stock stops really well, so I guess just luck of draw. They were all 97's but the last one was pre AEL, first and current ones AEL.
I deleted my abs valve as well using the stock prop valve. Out of master cylinder, into valve, out to the corners. The output closest to the booster is front. The prop has two out to the front calipers and one out to the rears. Do a tee split at the firewall to go all the way back. The local oreily stocks the right lines with bubble flares.
I would start by getting rid of any aftermarket parts you tried installing to fix this issue.
I would follow up by installing new genuine pads and calipers. You can put D90 front vented brakes and Defender 110 rear brakes.
I would follow up by installing new genuine pads and calipers. You can put D90 front vented brakes and Defender 110 rear brakes.
I bought a cheapy MC many years ago and learned a tough lesson. It locked up the brakes 5 miles from home and wouldn’t release.. I had the opposite of your problem… way too much braking. Agreed, get a TRW.
@jymmiejamz Running the vented rotor setup on the front. Aftermarket is only wilwood prop valve and braided brake lines. I made custom lines due to the length needed for my suspension setup. I dont buy cheap.
@robertf I could not get the TRW one origionally but the last one i put in was a TRW. Over the years i found they tend to come and go from stock at all my vendors, Years ago on my first disco i had to get the TRW one from an oregon warehouse because it was the only one left at any of the warehouses. i think i paid an additional 40$ for shipping just to get it. The aftermarket masters are all cheap cast metal. I try and only use the TRW ones for customers.
This car sat for a few years before i got it. I have had it for 3 or 4 years now and this is an issue from the get go so im on to the last couple things that could be it. Calipers and brake booster are the only things not replaced and it definetly does not seem like a booster issue. Im going to swap in some cheapie calipers just to test it with them. Ill rebuild the ones i have on there because they are oem and put them back on.
@robertf I could not get the TRW one origionally but the last one i put in was a TRW. Over the years i found they tend to come and go from stock at all my vendors, Years ago on my first disco i had to get the TRW one from an oregon warehouse because it was the only one left at any of the warehouses. i think i paid an additional 40$ for shipping just to get it. The aftermarket masters are all cheap cast metal. I try and only use the TRW ones for customers.
This car sat for a few years before i got it. I have had it for 3 or 4 years now and this is an issue from the get go so im on to the last couple things that could be it. Calipers and brake booster are the only things not replaced and it definetly does not seem like a booster issue. Im going to swap in some cheapie calipers just to test it with them. Ill rebuild the ones i have on there because they are oem and put them back on.
I've had good luck with refurb OEM MC's lately. My XD went thru 2 aftermarket MC's before getting one that actually worked. It's been on for several years now with zero issues. Recently I had to buy another MC for the 95 project and I went with refurb after having good luck in the past. Slapped the reservoir on it, bench bleed it, and installed it. Zero issues with it and the 95 project has a great feeling pedal.