She's a beauty, John! Gorgeous!

Thanks for sharing!

Don

 

Thanks Don, she does still look pretty good.
Today I added a litre of the TRW Mineral oil, by removing the large black reservoir cap. I made up a tube to fit the small filler hole, but gravity was not going to get it in there, so I just tried taking the cap off and pouring it in. The red mark in the level indicator disappeared, looked like a black shroud floated up to mask it. Started the car and all the warning messages were gone. On the test drive, the brakes started off about the same got better, but then went back to where some presses give great brakes and on other presses the pedal goes down to far, too easily and braking is not as rapid.
I think I will order new pads all round and spend next weekend replacing those, greasing caliper slides and all over inspection to see if I can see any issues and to know that the mechanical parts are all in the best condition. I still think there is some issues with the hydraulic booster, perhaps it will burp some air and all will be well.
In other news, the car started, after a week, so not rushing to replace the battery just yet, and I found a label applied during AC conversion to R134a. The boxes on it, date, charge weight, etc are empty, but expect they just faded over time. Car has one large high pressure port and one smaller low pressure which seems correct, matches other new cars and differs from friends R12 based system. I am pleased about that. Quick examination suggests the clutch is not triggering, so I will need to look up wiring diagrams etc.
Air flow from the vents in the car seems weak, could be related to low hanging ducting above passenger foot well? Fuel pump makes a LOT of noise when running, one window still does not work, has not magically fixed itself with no attention from me this week, but all four doors open with a lovely smooth action, so the lube job has stuck there.
Feeding of the leather continues, certainly seems more compliant.
Off to order brake parts and hide food.
Have fun,
John

 

Hi John,

It could be that in addition to the hydraulic boost system misbehaving, you may have some air in the brake system itself. Also, brake fluid is hygroscopic, so Jaguar recommends flushing the fluid every couple of years to expel any absorbed moisture.

The system has blower fans at the right and left ends of the dash, and they both blow toward the center. In fighting against each other, they create the higher air pressures we want from the vents. If one of the blower motors fails (for any of a few very common reasons), the remaining fan can produce only weak output from the vents. You can test the blower motors either by pulling their fuses one at a time to see if pulling one fuse makes no difference, or remove the knee bolsters and use a mechanic's stethoscope or long screwdriver or socket extension to listen to the blower housing. There is a lot of information in the XJ40 eBook at the Jag-Lovers forum. You may have to join to access the eBook, but it's free and well worth it.

Another common issue, especially on the '88-'89 cars, is that the dash may split along a mold seam on the back side (nearest the firewall/bulkhead). This dissipates the air pressure so you get far less pressure from the vents.

I believe our member Rob Evenson has posted about repairing this crack.

Cheers,

Don

 

Had another go at bleeding the brakes. I sat in the car and depressed the pedal some 40 times, engine off as it had been for 18 hours. Pedal was firm, little travel, for each push.
Assistant got in (young, non-driver), pedal was soft, long travel, then firm short for a number of strokes. Opened right front bleed nipple approx 60 degrees as pedal was held down. Fluid flowed into hose for about 2 inches worth, then ceased. Tightened nipple, pedal released and depressed again, soft, long travel, no fluid when nipple opened. Nipple closed, pedal up and down (reported firm, short travel) opened and fluid flowed. No air visible. Did left front, a little air came out, small bubble or two. Pedal continued varying between short and long travel. Did rear calipers in same fashion right side first, no air, pedal mostly firm, but if soft, then no fluid seemed to move.
Repeated bleeding of rears with the engine running (1988 model, expecting engine driven mineral oil booster system), very similar results, pedal mostly short travel, no air, an inch or two of brake fluid displaced with each press.
In all cases, as expected the pedal did move further once the nipple was opened.
I had seen comments that on the electric pump equipped later models, that brake fluid would flow if the pump was running and the nipple opened - that did not happen here.
Test drive gave same result as always, inconsistent response to pressing the pedal, sometimes great brakes, rarely moderate braking, sometimes very weak braking that is improved on releasing and repressing the pedal (sometimes the pedal was slow/sticking on being released, did not follow the shoe on the way up and would then catch up).
All pads look fairly new, all hoses look good on the outside, all wiring looks fine, but the dash does display low pad and anti-lock failure messages. Seller did comment that it had a new master cylinder fitted, it looks like he may have been chasing this problem for a while, hence new pads all round.
Any thoughts? Is the new m/c the hint, is there air somewhere still that is not moving? Is a hose collapsing? Or is it the accumulator?
In other news, the passenger door mirror had its trim reattached then it too was glued back onto the door frame/captive nuts that had been freed when the last owner smacked it off something. Confirmed the antenna is trying to go up and down, so will order new mast etc for that. Fitted new air filter too - small steps, but steps none the less.
I am off to read S-73 on Power Hydraulic Systems! Again!!

 

Not had time to do more on the brakes, but speed bleeders have arrived and a call to the previous owner confirmed brakes were okay initially, but master cylinder was leaking. Local tire shop installed new master cylinder and they have never been right since. I have a number to call and will speak to "Davey" this week to see if he bled the m/c on the bench before install.
In other news, the horn works, the exhaust mount has been replaced and has eliminated one rattle and the antenna was dismantled to find a broken piece of plastic in the gears. Adhesive has been applied and it will be left for a week to harden! Frozen locks on Monday led to the snapping of a retaining clip on the inner handle, so a new one has been ordered there, annoying to have a backward step in amongst the progress.

 

Well, it took a while, life got in the way, but I finally got a chance to get back to work on the car.
Following a chat with the garage (Davey) that had performed the original master cylinder replacement and the last owner, it was clear that they had a good idea of how to do the job well enough, and the brakes had been okay before they started, just fluid was leaking from the m/c. They had ordered another replacement, but the last owner never got around to taking it back in. Based on that knowledge, and seeing a reconditioned m/c for under $50, I ordered a replacement.
Fitted that today. Bled it on the floor of the garage first, in a vise, blocked off one port to match the arrangement on my car, and fitted two speed bleeders to the other two ports. Bled quite a bit of fluid through those, until air free, before moving it to the car. (I do see mention of easier bleeding using a big syringe, but did not have one to hand).
Fitting in the car was eased by having an assistant depress the brake pedal, pushing the actuator rod proud of the booster unit, making it easier to fit that into the m/c. Bolted it loosely to the booster, then removed the speed bleeders one at a time and fitted brake pipes in, then tightened the bolts to the booster (this allowed a little movement in the m/c unit when connecting the brake lines).
All felt good (I had actually also bolted it tight to the booster with the speed bleeders still in place and confirmed the pedal was firm, and therefore the m/c was not leaking internally) and I actually took a trip round the block to confirm the pedal remained firm and consistent and braking was efficient.
Back into the garage, wheels off, swap in the new speed bleeders to each caliper, bleed each corner, then I took out each abs sensor and cleaned the gunk off them, then took each caliper apart and cleaned and lubricated the moving parts.
A longer test drive confirmed typical braking, if not the best stopping power, along with consistent pedal feel, they worked first time everytime, so I am crediting the master cylinder change with correcting the inconsistent pedal feel.
Unfortunately the anti-lock failure message came on, went off and came back, so more research needed there, outer coating of some wires was missing/cracked, will maybe tease the relay open too.
We also leatherique'd the seats, lubed the sunroof channels and fitted the new antenna grommet, so more small steps have been made. Antenna failed again after gluing, small piece that links two cogs inside is broken, cannot discern its function, so do I just glue them together, or look for replacement parts?
Need steering rack boots, then attention to the a/c before it gets too hot here.

 

Not had much time to work in the car, so she sat in the drive doing nothing for a few weeks.

Issue now is the leak from the gas tank.
Running it nearly empty and leaving it in the drive reduced the smell in the cabin to not-detectable levels. I climbed in the trunk and tightened three visible hose clamps and inspected all I could see for obvious problems. nothing was apparent, and being the eternal optimist, I went and filled the tank (19.97 US gallons of 91 octane). Smell returned after a short drive. There was evidence of moisture.gas on the top of the tank, near the lump that sticks up and the vent hose, but no clear sign o a hole, nor significant looking corrosion.

I have been to the pharmacy today to buy talc and will coat the top of the tank looking for clearer indications of where it comes from. Hopefully somewhere visible, in which case I will clean up the area and apply some JB Weld, hopefully avoiding the issue of removing the tank. If not, then there will need to be a discussion with her indoors about how long I can block her bay in the garage with a stuck XJ40.

Recently added a new stereo, replaced the subwoofers (let me know if anyone wants my source for those), fed the leather and added blind spot mirrors.
Still have one window that does not open and a hot water valve that does not close, but we are slowly making progress.