Brakes locking up -98 Discovery 1 - Help!

terryjm1

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Jan 23, 2011
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I have a 98 D1 that I converted to 300TDI with 5 speed. It has been a long term project that is now on the road after years of inactivity. After I first got it drivable I went on a short run including the interstate, about 10 miles. Unfortunately, the brakes heated up to the point they almost completely locked up. I let it sit in the driveway overnight and they had released. As the brakes were very old and were unused for years, I decided to replace almost everything.

Here is what is new:

All 4 calipers and pads, (front D90 vented)
Front discs
All brake hoses replaced with braided stainless steel
Brake master cylinder

The only part that had been replaced before that test drive when the first locking problem occurred was the master cylinder.

Well, I took it out for another test drive today, after replacing calipers, pads, and hoses. (I also installed 2” lift springs and shocks, not that it matters) This time I only made it a few miles and didn’t make it home. After it sits for a while it eases up and you can move it. However, I only made it about a 1/4 mile and they were locked up again. I am going to give it a few hours and go back to see if I can nurse it home. Also, the brake pedal is as hard as rock when it reaches this point.

The only old stuff left is the prop valve and ABS unit. Could they be causing pressure to be held in the lines? Maybe I got a bad new master cylinder?

Any idea what could be causing this?

Thanks in advance!

Terry
 
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terryjm1

Well-known member
Jan 23, 2011
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It has been so long I will have to look at my receipts to find out the brand. However, I am thinking the MC is the problem. I’m going to crack open the line at the MC and see if it releases the pressure. Just have to wait for the wife to come home to take me back to where I had to leave it parked.
 
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terryjm1

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Jan 23, 2011
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In threads I could find addressing this issue, no one posted back conclusively what resolved the problem. So, I am not going to be “that guy.” installed another master cylinder sold by Britpart (from Land Rover Direct) to replace the one I picked up on Rockauto. The problems completely went away after I installed the Britpart master cylinder. And, the abs light that had been on since I bought the truck went out. I have since driven it 120 trouble free miles and the brakes work better than ever. Lesson learned, don’t buy an off brand master cylinder. Thanks to those that suggested this was the issue.
 

Tugela

Well-known member
May 21, 2007
4,754
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Seattle
I don't think I would feel safe driving a vehicle with a Britpart master cylinder. That is a scary item to have fail in any way.

What would you suggest as a preferable alternative? I'm anticipating needing to replace this part eventually so would like to know for future reference.
 

jymmiejamz

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Dec 5, 2004
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Los Angeles, Ca
What would you suggest as a preferable alternative? I'm anticipating needing to replace this part eventually so would like to know for future reference.

I don't know what the options are, to be honest. I'd be inclined to rebuild an original one before using a Britpart one.
 

ezzzzzzz

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Apr 22, 2010
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I hear complaints about britpart but have never had a failure in over 25 years and dozens of trucks. Maybe I just got lucky. Try unplugging the abs module and see if the problem persist. Ignore the dash lights while doing this. The only recourse is to follow logical troubleshooting. By the way, could it be the parking brake or do the calipers reek of burnt pads after that short run?
 

terryjm1

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Jan 23, 2011
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Reread my solution reply. The Britpart mc solved the problem. On the question of Britpart quality, I have found at least on some parts, they are simply reboxed oem parts.
 

WaltNYC

Well-known member
Mar 3, 2010
707
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NYC
Britpart is really 'uneven' in quality. Buyer beware indeed.

For example I bought a hood release cable which failed on the very first pull (wire not crimped well enough into the end piece).

 

terryjm1

Well-known member
Jan 23, 2011
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Lol, great post. The problem mc was another brand and I bought it so long ago from Rockauto I can’t remember what, probably raybestos or another common supplier. However, it was not Britpart. I can agree Britpart likely puts out some junk, like your hood release cable. The mc I received so far fits and works perfectly.

Another Britpart item I purchased was an AC compressor. It was literally identical to the LR part, same oem supplier, but over $500 less.
 
Regarding Britpart, it must be taken into account that this provider offers for almost all items (or part no's), the 2 alternatives: Genuine (suffix "G") or OEM / alternative (without suffix).
In the latter case, depending on the occasion, spare part can be OEM and its quality similar to genuine one, or an alternative that is not usually of good quality. It may be convenient or logical to use it for its low price, although in most cases it is not directly recommended. In my experience and my mates do not agree for example rubber parts (bushes, hoses) and worst of all: syncros for R380 box:eek:.

"G" suffix are ok, but BP sales agents try to prioritize the others because they give more profit;).

Regards
 
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jymmiejamz

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Dec 5, 2004
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I hear complaints about britpart but have never had a failure in over 25 years and dozens of trucks.

Here is a great example of a Britpart failure. My coworker decided to replace his original rotoflex with one from Amazon. The one he got was Britpart. It lasted about 22 hours.



The same coworker bought a Britpart idler pulley (purchased at the same time as the rotoflex). It lasted about 500 miles. He had to be towed to the shop as it was a catastrophic failure on the highway. The bearing totally fell apart.
 

terryjm1

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Jan 23, 2011
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Just as an FYI, Land Rover Direct offers several brands if you loooking for a replacement. If I were to do it again, I’d go with TRW. Using their catalog isn’t the best. I usually find the part number I need from another source and then go to he their website and search using the part number. If they had a better online catalog system, I’m sure they would sell a lot more.


For now, I’m hopeful my Britpart is a repackaged OEM part. Visually it looks like a quality item, fits perfectly, and bled quickly. If I have a problem with it, I will update the post or start a new one. Maybe I will start a new one titled: Post your Britpart experiences! I was unaware of the huge question marks on Britpart as a relatively inexperienced Land Rover owner. As such, I have several Britpart items on my ride. (So far my hood release cable is aok).
 

p m

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Apr 19, 2004
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Missed the thread.

Long time ago, I had a British Ford Transit van that's been in a head-on collision. After the van was repaired, the brakes tended to lock up after several applications; the pressure has been building in the system and not releasing. For a couple of weeks I honed up my skills in driving without using brakes, then gave up and started looking for a cause.
Apparently, the diaphragm of the brake booster had shifted a couple of c.h., which was enough for the piston in the master cylinder not to clear the pressure release ports. Made a 3mm spacer out of aluminum sheet, the problem went away.
I suspect there was nothing particularly wrong with the MC you took off, and the problem could have been resolved with a similar spacer. It's a hack solution, but not a dangerous one.
 

ezzzzzzz

Well-known member
Apr 22, 2010
604
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Here is a great example of a Britpart failure. My coworker decided to replace his original rotoflex with one from Amazon. The one he got was Britpart. It lasted about 22 hours.



The same coworker bought a Britpart idler pulley (purchased at the same time as the rotoflex). It lasted about 500 miles. He had to be towed to the shop as it was a catastrophic failure on the highway. The bearing totally fell apart.

I don't discount that people have problems with Britparts. I'm simply stating that I haven't experienced these problems. That said, I do try to avoid the LR parts and their high prices. I try to find a good deal without buying junk. Compromise where I can and spendy where I have to.
 
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terryjm1

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Jan 23, 2011
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Posting back about my problem. If you read above you know my problem was an off brand master cylinder causing my brakes to lock up. I installed a new Britpart master cylinder and it resolved that problem. It worked great for 1500 miles, no problems. I have since relocated the D1 to our mountain cabin. “Town” is 26 miles away and an elevation drop of about 3500 feet. On the climb back up the mountain I don’t touch the brakes for about 30 minutes and the engine runs at relatively high rpms due to the 300tdi not having great horsepower. When I depress the brakes after that climb the pedal goes to the floor. It takes at least 2 pumps to get the pedal about half way up and that is as good as it gets. After driving it at lower speeds with several stops it returns completely to normal full pedal. There is no fluid loss. No air in the system, either.

All of my research points to the bypass in the master cylinder malfunctioning. I have ordered another mc, this time a TRW oem unit. As the booster is 21 years old, I am going to replace it at the same time.

So, if the problem is the mc, this experience is a bad Britpart experience and will effectively cause me to dismiss buying any Britpart item (unless it is a G suffix) that is anything critical.

I hope to complete the job next week but with needing to head back home (Land Rover stays at Cabin) if the parts don’t arrive in time it will have to wait until spring when we are back at the cabin.

Short of the prop valve, hard lines, and abs unit, everything in the braking system will be new after this job is done.

While my abs unit seems to work great, at some point, I’d like to install a refurbished one. Anyone have suggestions on where I can get one?
 

Swedjen2

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Sep 12, 2018
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California
Posting back about my problem. If you read above you know my problem was an off brand master cylinder causing my brakes to lock up. I installed a new Britpart master cylinder and it resolved that problem. It worked great for 1500 miles, no problems. I have since relocated the D1 to our mountain cabin. “Town” is 26 miles away and an elevation drop of about 3500 feet. On the climb back up the mountain I don’t touch the brakes for about 30 minutes and the engine runs at relatively high rpms due to the 300tdi not having great horsepower. When I depress the brakes after that climb the pedal goes to the floor. It takes at least 2 pumps to get the pedal about half way up and that is as good as it gets. After driving it at lower speeds with several stops it returns completely to normal full pedal. There is no fluid loss. No air in the system, either.

All of my research points to the bypass in the master cylinder malfunctioning. I have ordered another mc, this time a TRW oem unit. As the booster is 21 years old, I am going to replace it at the same time.

So, if the problem is the mc, this experience is a bad Britpart experience and will effectively cause me to dismiss buying any Britpart item (unless it is a G suffix) that is anything critical.

I hope to complete the job next week but with needing to head back home (Land Rover stays at Cabin) if the parts don’t arrive in time it will have to wait until spring when we are back at the cabin.

Short of the prop valve, hard lines, and abs unit, everything in the braking system will be new after this job is done.

While my abs unit seems to work great, at some point, I’d like to install a refurbished one. Anyone have suggestions on where I can get one?


Try these guys - https://www.falconworks.net

They are in Tucson, AZ. and have some interesting fixes/upgrades for one and all. At least give'em a call.
 
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salvvia

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May 28, 2005
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BIG WHEEL ROVN IN KNOXVEGAS TN.
Pull the abs fuse years ago. it may resolve the whole issue I pulled mine after my truck rolled me through a stop sign. only difference is down hill on ice mud and blood it likes to lockem up . everyday driving is no problem

Keep us posted though i may need to replace my 23 yr old brakes as well
 
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terryjm1

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Jan 23, 2011
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The master cylinder and servo arrived today. One note on the TRW master cylinder, in spite of it being shown with a reservoir (Rimmer Brothers), it does not come with one. There was no notation in the listing that it came without one. LR Direct was out of stock, which is why I went to Rimmers.

I was planning to return the Britpart master cylinder but it looks like I will have to keep it so I can use the reservoir.