Noise from abs modulator...?

[benji]

Just had my brother over with his 99model. After a bit of a drive we could hear a very faint noise from the motor side of the abs modulator. The keys were out of the ignition.

Has anyone else noticed this?

Also, would anyone know if a weak shuttle valve would cause the traction control to be weaker than it should? My cousin basically has the same problem on his 02defender. When the axles are crossed up in mud the tc isn't strong enough to break traction on the other wheels.

[bsperka]

No noise isn't good. If car is sitting for a long time, it will flatten the battery.

[strangy]

Noise something like a pulsing at high frequency is normal.

[dswatts]

Mine does it, been told its normal.

[schuy1]

Have heard it described as a "Space Invader" sound :D perfectly normal and if your battery is in good nick wont flatten unless over a long time. 300milliamp draw I think.
Cheers Scott

[Robgw]

A very quiet ticking sound like an electric clock is normal i've been told..

[ozscott]

Electronic woop, woop is perfectly normal. I noticed it when I bought the car new in 2002. Never caused a flat battery. The batteries in my D2 last 4-5 years.

Cheers

[OffTrack]

Also, would anyone know if a weak shuttle valve would cause the traction control to be weaker than it should? My cousin basically has the same problem on his 02defender. When the axles are crossed up in mud the tc isn't strong enough to break traction on the other wheels.


It's unlikely to be the shuttle valves. The shuttle valves respond to pressure in the lines from the master cylinder (ie when you press the brake pedal) and switches between two "circuits" the brake fluid travels along depending on whether the brake pedal is pressed or not. The valves also activate the shuttle valve switch to signal the SLABS ECU when the pedal is pressed.

The portions of the Modulator that are used when the TC is running are the return pump, and the outlet and inlet solenoid valves.

cheers
Paul

[benji]

A Space Invader, that's it! We worked out it's in 6/8, and it's in D# major, andante.

Cool, thanks guys.

Just got to sort out the tc. The tc on my 93 classic is more effective - so something is amiss.

You can here it working but it's just got no bite to it, if you lifted a wheel on the flat the etc won't get it going.

[schuy1]

Brake pads seem to have a great deal of bearing on the amount of braking during TC events. Old or hard pads do not work as well. The factory spec pads seem to be the best, though a little dusty and do not last as long with heavy usage.
Cheers Scott

[ozscott]

True. Its amazing the difference. Stock are good. Ecb are a smidge better.

Cheers

[Tombie]

Just had my brother over with his 99model. After a bit of a drive we could hear a very faint noise from the motor side of the abs modulator. The keys were out of the ignition.

Has anyone else noticed this?

Also, would anyone know if a weak shuttle valve would cause the traction control to be weaker than it should? My cousin basically has the same problem on his 02defender. When the axles are crossed up in mud the tc isn't strong enough to break traction on the other wheels.

The TC in mud / water is less effective as the brakes are effectively wet.

A softer pad (more dust and faster wear) or a slotted rotor (helps clear the pad to disc surface quicker) will assist.

The ticking is normal, and stops after a while.

[OffTrack]

The other thing to bear in mind that it is Traction Control. You will always be limited by the amount of traction available.

In the situation described - cross axled in mud, the limiting factor will the amount of grip available to the wheels touching the ground. The ETC will apply braking to the wheel in the air up to the point the wheel on the ground starts to loose traction and will then back off the braking to ensure that power is transferred to the limit of the available traction.

What you shouldn't ever see is the ETC braking a wheel to the point that the opposite wheel spins.

cheers
Paul

[benji]

Thats just my point Paul, no matter what the surface from slippery clay, sand, rock scree the wheel not being controlled by the etc wont even come close to breaking traction. Even the front end up a steep incline on shaley rock, it won't shunt the torque across.
From watching many a youtube clip theres something amiss.

Thanks for the suggestion about the pads guys. Ill pass that on.