Hi all,

Two completely unrelated questions.
Working on an '89 coupe V12.

First, there is a coolant temperature sensor on the B bank behind the air cleaner. It screws into the coolant pipe and has two small diameter vacuum hose connectors coming out of it at a slight 'V' angle. Q: What do those hoses connect to?

Second, this car car has Teves ABS. I replaced all the brake hoses, calipers and pads last winter using my friends lift. Bled front brakes no issues. Tried to bleed rear according to the procedure but got no fluid. (turn ignition to ON for no more than 15 seconds, open valve, press brake pedal, close valve, turn to OFF, wait 1 minute, repeat) Brought the car home on a flatbed a week or so later. Removed the unit on the passenger side of the engine compartment and drained all the old fluid including what was a lot of gunky stuff in the pipes (this car had been sitting in a garage for 15+ years). I won't have an assistant to help with attempting to bleed the brakes again for a week or two. Q: Can I unplug the electrical connector for the accumulator and then connect a battery to the car to test my other electrical components without burning up the Teves accumulator unit. It seems obvious that it should not be an issue but .........it's a Jaguar. Many thing are not what they would seem at first. Want to verify first.

Thx

 

The coolant vacuum sensor sounds like something to do with USA emissions requirements & all the related bits n pieces - fairly sure my UK market 1989 V12 doesn't have that, only electrical sensors with either 1 or 2 wires.

2nd question - yes you can just unplug the connector that goes to the motor underneath the accumulator. Then when you turn the key to ignition on, the pump just won't run/won't charge the accumulator. It will likely result in ABS/brake fault dash lights being on.
It shouldn't be possible to burn the pump up though unless you are actively bleeding the rear or have a massive brake fluid leak - if everything is working properly, the pump will run for 30-40 seconds, or whatever it takes to charge the accumulator, then stop.

 

Thanks. Yes it's a NA car.
Neither my parts manual nor Haynes Repair Manual shows the vacuum routing for this. I did note that my spare engine, an '88, also has the temp sensor hoses cut off at about an inch. Could it be the sensor was just used a plug?

Keeping my fingers crossed that the Teves ABS bleed goes well this time and I have fully functioning brakes.

 

Bradscat,

If you have disturbed the pump / accumulator and or drained the reservoir, you really need to bleed the low pressure side of the system, before you start on the wheel circuits. If you have any air in the feed pipe to the pump or air in the pump / accumulator, you will not be able to bleed the rear wheel circuits properly.

Good luck

Paul

 

Okay. This is all new to me.

Was not aware there is a low pressure and presumably a high pressure side to the system.

I am not familiar with the term 'wheel circuits."

Thx in advance

 

Brad; The low pressure side is the line between the brake reservoir and the pump. The high pressure side is from the pump to the rear calipers. As per our conversation a while back you told me that you flushed out the low pressure side. i.e. the line from the brake reservoir to the pump.

 

All,
Figured out the coolant temp sensor vacuum lines. Its not covered in the Haynes Manual or the XJS Parts catalog so a bit of challenge. Its in Emissions category but does not appear to have anything to do with how well the car runs. hence why all the examples I saw had the hoses cut off. Anyway a couple of "T" connectors and everything is hooked up similar to originally manufactured.
Next up is the front sway bar. I think I tried to put it in upside down. The bar needs to point down.
The manual say to use a ball joint separator to remove the left side tie rod from the steering arm. Is this absolutely necessary? Thx