New, Used, Rebuilt ... which way to go???
We are a Land Rover specialty shop, and we repair and
restore these pumps worldwide. So we thought it
might be helpful if we share some tips based on what we see out
there.
Of course we'd love to sell you a copy of our book for diagnosing Range Rover ABS brakes, Getting Comfortable with WABCO ABS brakes, Range Rover 1990 to 2002, eighth edition, but it DOES NOT have all this anecdotal stuff in it. Prices and information cited on this page are approximations, current in fall, 2024.
New Range Rover Classic ABS brake pumps, as of summer 2015, became extinct ("NLS"). If you can ferret out a complete new unit, this is a jewel. But for us mere mortals, the decision falls into two categories. Repair the one you have, or have it fixed; or buy a used one. In deciding how to approach this, it might help to think of the pump assembly as three distinct components:
* The Motor
* The Pump body
* The Pressure Switch
The motor is usually easy to remove. if not corroded. Three
Allen head cap screws hold it on.
Be careful to hold the motor upright, above the pump
body, so as not to lose the loose parts inside that are retained
by the motor. The red
lead on the motor is hot, and brown one is earth.
Powering the separated motor it should run, and it should
draw less than 5 amps without a load.
If it is not a runner, or draws too much, it can be
fixed.
Also, new knock-offs have become available.
They are actually a cute re-design, but unfortunately are
underpowered.
We've had any number in the shop for repair already, and
they can't be fixed; we don't even try any more.
Also, all the parts inside are different and
unavailable. If you do opt to try one be sure to save you old
WABCO core!
Usually the
original ones can be rebuilt, even if melted-down. The motor
end-cap is staked on, and great care must be taken when opening
it if the motor housing is to be re-used. We sell some
of the common parts if you prefer to try it yourself, or you can
send it in and have us do the overhaul. We offer
cosmetic restorations as well. While ours may cost more than the
Chinese versions are new, now that the jury in it seems much
preferable to have your old one fixed.
Even if you do decide on a cheapo replacement, be sure to
save your old WABCO one, just in case.
Make sure to replace the seal ring to the pump body, and
the shaft seal, and that not a trace of dirt gets inside the
opening in the pump body while the motor is off.
The brake pump generally lasts a long time. On Classics the failures
are usually noise, or poor flow, or both.
The integral internal filter screen will get blocked,
most commonly. Additionally the rotor bearing and/or plungers
can also get worn, the pressure-limiting valve can leak or wear
out of range, and the outlet check valve can leak.
All these can be repaired.
If you send to us a working or marginal pump assembly for
overhaul or repair (and we always estimate before any work) it
will cost less than a seized-up junkyard core.
If doing the work your self, your #1 suspect, the
filter screen is not removable. After the pump is
stripped, block the little vent hole just above the bearing
outer race with a drill bit, submerge the unit in hot soapy
water, and use a large suction syringe on the inlet fitting port
to back-flush the screen.
The pressure switch is easily removed from the pump body, if not too corroded, or torqued in there by a bull moose. It takes a 36mm thin-wall 6-point socket, and should be torqued to about 10 lb/ft. These, sadly are no longer available new. We can usually rebuild your old one. Make sure that not a trace of dirt gets inside the opening in the pump body while the switch is removed.
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USED UNITS: What good is a used pump, then? If it has an original WABCO motor that runs, and doesn't leak, it has some value. If it has a pressure switch that still works, and doesn't leak, that has value. As for the pump body itself, if that's the only problem with your old one it is wiser to get yours serviced than buy a dirty old used one ... one which probably needs a cleaning a service worse than yours.
RECAP: New pumps have gone the way of the dinosaur. Used pump assemblies can be considered for the motor, if your old motor is non-running (open circuit or short, AKAfried) and you wish to swap it out. Fitting the whole thing risks introducing contaminants into your system. Working used pumps can of course be refurbished, and it will cost less for working ones than for fried pumps. So it could be cost-effective to buy a used pump that works and have it rebuilt, as opposed to having your toasted open-circuit motor unit done.
TESTING: Our Range Rover brake book does explain in
detail how to test these pumps while still on the car.
If you have obtained a used unit you want tested, we can
run it on a test bench, and estimate any repairs needed for $59,
if you want to send
it in. We can test motors, accumulators and pressure
switches separately as well, if you like.
ESTIMATING: Estimating necessarily results in teardown to some
degree, and if you decline the work we will return the unit in
pieces. So please be very clear when we call you if you only
wish testing and do not want estimating.
COSMETICS: Unless you
prefer otherwise, we re-plate the motor body in yellow zinc,
the pump housing in clear zinc, as original. We us black
screws, yellow bleeders and inlet fittings, and clear zinc
outlet fittings. We now have new repro plastic tail caps. It
will look like the unit pictured (except the Allen screws). If
you prefer different colour combinations, please let us know.
We think a restored Classic Land Rover with a spray-painted pump
looks a bit pathetic ...
RELIABILITY: The original WABCO assemblies almost never wear out or fail of their own accord. If the accumulator and relays are kept good, the brake fluid periodically flushed, these are perhaps 250k mile units. Pump faults are almost always caused by other things -- things which you, the well-trained owner, can usually tell well in advance. Do not blend brake fluid brands, stay on top of accumulators, relays, clean fluid, and monitor pump run-times. If you read the book so there's no reason to need to buy another pump! Just sayin'.