Hi
So first time trying to get the old girl moving since November. Started up well and running but Brakes super spingy and very limited response…I checked the brake resovoir level and one was low so thought I might top up for short term before further investigation…just want to get her back in the garage without driving through it!
Any thoughts let me know
B
PS any particular fluid to top up with??
Castrol LMA DOT 4 if you can find it, otherwise any DOT 4 reputable brand is ok. I use Prestone.
When you say you checked the level and ONE was low, do you mean you also checked the clutch reservoir? Watching the fluid level is one way to watch brake pad wear and determine other leaks in the system. frequent topping off indicates problems and does not allow one to watch the level SLOWLY go down as brake pads wear down normally. Does your dash light illuminate when you press down on the button on top of the reservoir?
As brake fluid is hydroscopic you may have accumulated a bit of water and bleeding the brakes would not hurt. I once found a bit of green/blue goop in the right rear cylinder after only two years.
Gerard
I’m with Gerard, only one MC for the brakes (some other Jags have two) - if fluid bottomed expect you have some air, a leak and a check and bleed job to do. I have just done mine - after changing the timing chains. Got to love that - brake bleed and timing chains in the one sentence - all part of the one job. Must be a Jaguar! Paul
Hi,
Thank you for responses. The two brake fluid bottles that sit close to drivers side …onf these was low in fluid. This I topped up. I have not examined the reservoir…
I am not likely to get the car on the rd so not really concerned aside from managing the drive in and out of garage for now. At present, Brakes are super spongy and really not functioning.
I attach a pic …it’s the grey car and slowly being upgraded from spare for the blue.
The Mark X had two brake reservoirs: one is for the master and input side of the servo, the other is for the secondary side of the servo and the calipers.
The clutch reservoir is smaller.
Clamp off the vacuum hose to the Servo. Does the pedal get harder?
If the car has sat for a long time and you bleed by pumping the pedal you may find that the M/C starts leaking pretty soon after that. What happens is if the M/C is corroded, moving the brake pedal full stroke can scrape the seal past a corroded area that it normally doesn’t reach. If at all possible use a pressure bleeder to flush 250ml out of each caliper bleed nipple - if the system has no air in it when you start flushing then pressure bleeding won’t introduce any.
If you have to bleed by pumping just be aware that you may notice a degradation in the seals not long thereafter.
OK, my error - I construed a Mk2. Must be similar to e type series 1?
Hi
trie dthis but no change.Have never explored brakes before… how do I measure the levels in resevoir?
thx
B
With the cap off the fluid should be about 3/4" below where the container curves in towards the threaded bit. There is usually a line cast into the body of the reservoir.
If your level switches aren’t working because the float has stopped floating, remove the Al sleeve and replace the float with wine cork from a regular 750ml bottle which has been sitting in a kitchen drawer for long enough to dry out thoroughly - white wines usually leave no deposit whatsoever on the cork. I actually have a couple of washed and dried corks in a drawer of my toolbox, ready to fit.
Cleaning the contacts at the top is pretty straightforward too, just take the two screws out and clean the crud out.
The bottles themselves usually clean up with soap and water, or petroleum distillate like Varsol or Turpentine. Don’t use anything hotter than those as they may make the plastic brittle. Blow the container out with compressed air, and leave it to dry thoroughly before you refit it.
If you can’t find a leak at any of the cylinders you may find that either your servo, or your Reservac are full of brake fluid. This means time for a servo rebuild. I generally try to rebuild the whole system at roughly the same time if the car has sat for a long time - this costs more if you end up replacing/resleeving cylinders, but once you’re done you know that the brakes are back to new, and all you need to do is flush the system every 2nd year or so from then on.
It all sounds quite complicated…
I think I’ll try to bleed system first and then explore other options if this does not help.Would the attached be the correct device to attach for bleeding or something else?
Isn’t that the hose that goes between the rear axle and the car body for brake line connections. Might also be the front hose line? Got a part number on that puppy?
Gerard
Bear,
Bleeding the brakes is a relatively simple and inexpensive first step. All you need to bleed the brakes is a spanner which fits the bleed nipples, a 2-3 foot length of clear hose, a jar or bottle to hold the old fluid, a can of fresh fluid to top up the reservoirs, and someone to press the brake pedal.
Bleed each corner until the fluid coming out is bubble free, and clear like the fresh fluid.
The Shop manual details the procedure, but it is pretty much the same for any hydraulic brake system.
Just be aware that if the car has sat for a long time and there is a buildup of crud or rust in the part of the bore that the M/C doesn’t normally reach, then this may damage the piston seal. You get a nice firm pedal while bleeding, but not long after that the pedal will slowly sink to the floor. Then it’s time for a rebuild, or replacement if the M/C,
Your picture shows a flex line. That one is either between the hard line under the floor and the IRS, or possibly the clutch slave. There another two similar hoses at each of the front wheels, but I think they are longer than the one you’ve shown.
THank you for the detail. I will give that a go … IS it necessary to remove the wheel oe able to access the nipple with wheel still on? Just it is a little soft around the jack points and causious accordingly.
B
At the rear you need to remove one of the shocks to get to the nipple, iirc. And at the front yes, you need to remove the wheel as the bleed nipple is on the outboard side of the caliper.
O.K. thank you…are there aother secure areas to option jacking up ?
Using a floor jack and a piece of scrap carpet jack up the car in the middle of the IRS rear differential area. Do not jack up the car on the axle shafts .Use of jack stands is advisable for added safety. In the front there should be secure areas besides the jacking points that will hold the weight of the vehicle. Slowly jack up the car and get a feel for what is happening with the load. You do NOT want one of these big cats landing on you body.
I believe there is a part available so you can extend the bleeder nipple so that future bleeding is much esaier. I ask the list for this information on an extension hose which hangs down below the IRS a bit.
Also check that you have plenty of pad left and replacement may be in the near future. ALWAYS check your brakes in a safe/slow area after doing any work such as this.
Gerard
??.. one resevoir for front circuit and one for back I am 99.99% sure
there will be air in there
the rears will be seized and stuffed probably, big job
if they feel spongy that will probably be the front, do them first, they are easy.
open the front bleeders and fluid should run out with gravity,if it wont the front hoses are partially blocked and need replacing…replace all 3 rubber hoses if they are more than 10 years old
you will see fluid flowing from one resevoir only…keep it topped
worry about the rears later, car will feel fine with just fronts, so long as not being driven under full road situation
if the car hasnt been looked after, the front brake pistons will probably be cactus too, its an easy job to split the caliper, use the car hydraulic to push the pistons out, maybe u will be lucky, but new pistons and seals for front are not too expensive
I stand corrected, the MkX 3.8 manual says exactly that.
(I was thinking of the E reservoir system)
i was thinking of the 4.2 system, dont know much about the 3.8 mkx brakes resevoirs
