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View Full Version : ABS booster/modulator replaced successfully!



glenhendry
11th October 2013, 08:59 AM
Hi guys

Last night I successfully replaced my ABS modulator/master cylinder/booster unit. As per this thread (http://www.aulro.com/afvb/p38a-range-rover/183462-under-bonnet-seals-warning-do-not-remove.html#post2003952), the reservoir was damaged by heat and then when we were investigating the unit for damage, the black plastic (13pin male) connector embedded in the modulator unit was pulled out which tore the "computer ribbon"-like wiring between the connector and the modulator internals, rendering ABS Faults and Traction Failure.

Luckily I had a spare ABS unit and reservoir from a wrecked P38 I bought ages ago. I wasnt sure of its utility, but it seems to have worked out. All of the bolts and connectors are accessible, and nothing was overly difficult. Disconnecting the unit from the brake pedal is scarily easy. The main problem is that RAVE notes the ABS unit as unservicable, so there are very little information on it in RAVE.

Lessons:
- You do not need anything like the 4 litres of brake fluid I see quoted to bleed the brakes, I only used about 1.8 litres, from a dry reservoir tank and everything disconnected.
- You can change the ABS booster/modulator and Faultmate doesnt care, either do any of the other P38 computers.
- You do not need to disconnect the main battery to do this job.
- Total working time (alone for the ABS unit work, then with a partner for bleeding) was 5 hours, including a short break for dinner.
- There are multiple ABS booster units, this most wonderful microcat site (http://lrparts.net.ru/), lists SXC100010, but my unit clearly had SXC100000, and so did the spare unit I had.
- Do not attempt brake repairs unless you are competent and confident, and test afterwards carefully. Follow RAVE instructions for bleeding and remember that the system is highly pressurised. Read the manual first.

mtb_gary
11th October 2013, 09:42 AM
Hi guys

Last night I successfully replaced my ABS modulator/master cylinder/booster unit. As per this thread (http://www.aulro.com/afvb/p38a-range-rover/183462-under-bonnet-seals-warning-do-not-remove.html#post2003952), the reservoir was damaged by heat and then when we were investigating the unit for damage, the black plastic (13pin male) connector embedded in the modulator unit was pulled out which tore the "computer ribbon"-like wiring between the connector and the modulator internals, rendering ABS Faults and Traction Failure.

Luckily I had a spare ABS unit and reservoir from a wrecked P38 I bought ages ago. I wasnt sure of its utility, but it seems to have worked out. All of the bolts and connectors are accessible, and nothing was overly difficult. Disconnecting the unit from the brake pedal is scarily easy. The main problem is that RAVE notes the ABS unit as unservicable, so there are very little information on it in RAVE.

Lessons:
- You do not need anything like the 4 litres of brake fluid I see quote to bleed the brakes, I only used about 1.8 litres, from a dry tank and everything disconnected.
- You can change the ABS booster/modulator and Faultmate doesnt care, either do any of the other P38 computers.
- You do not need to disconnect the main battery to do this job.
- Total working time (alone for the ABS unit work, then with a partner for bleeding) was 5 hours, including a short break for dinner.
- There are multiple AB units, this most wonderful microcat site (http://lrparts.net.ru/), lists SXC100010, but my unit clearly had SXC100000, and so did the spare unit I had.
- Do not attempt brake repairs unless you are competent and confident, and test afterwards carefully. Follow RAVE instructions for bleeding and remember that the system is highly pressurised. Read the manual first.

Well done, following the bleed procedure makes for interesting reading, and then actually doing it. Like yourself I had my wife in the car pushing down the brake pedal and turning the ignition on and off, I was thankful for the help. I have had to do this a couple of times now after an ABS modulator rebuild went pear shaped :(. All good now though ;)

Gary

Hoges
11th October 2013, 12:36 PM
Excellent result...esp. finding the wire disconnect!
Thanks for the details
cheers