I am new to classic cars and Jaguars. Last Sunday, dawn, took the 1959 Mark 1 out for her maiden drive ( under my ownership) car ran pretty good but discovered that… BRAKES !?! were not working very well. Seemed like initial push on brakes produced some pressure, but then the pedal went flat to the floor. Repeatedly - like every time I went to stop. Got home safe -10 miles. Double checked to verify that brake fluid is in reservoir and no sign of any leaking. Thought I’d just bleed the brakes but got to thinking - how does one pump out brake fluid if there’s no pressure ? So I’ve spent 2 days researching threads and talking with the mechanic for former owner ( 850 miles away). Master cylinder was allegedly just rebuilt be some guy with a great reputation - maybe in South Carolina? Anyway, I’ve been reading threads about air locks, bench testing, kits to help with brake bleeding, air in master, special equipment, servo problems and rebuilds etc. to the point that my head is just spinning. Not at all sure how to proceed at this point. Any and all suggestions, ideas and insights will be, as always, greatly appreciated !
Schmitty
Should have clarified that this car has the disc brakes.
Sounds like your master cylinder is failing. The seals inside are bad or the bore is damaged. You can still bleed the brakes, as you still have some pressure and you don’t need much to bleed the system. Actually you can just let gravity do it or a pressure differential. Bicycle hose over reservoir or a vacuum, I use a spray bottle sprayer to suck it out.
that usually a sign the master cylinder seals are bypassing
For a master cylinder that age, it would almost certainly should have ben re-sleeved
In my opinion, you should remove the brake master cyl, and have a brake specialist inspect it to se if it has been sleeved, and put a new brake seal kit in it
unfortunately, you cannot ignore a MC problem
By all means try and bleed it first. Start with the master cyl
What you describe is looks like the master brake cilinder, time for a replacement?
At some time just new seals will not help anymore ( internal wear/ damage ? )
Did you check the remote brake servo?
And check the old ( 3 ) flexible brake hoses.
When they get old they will internally disintegrate, and blocked inside.
Well, I’m upset and a little mystified. the former mechanic has told me over the phone " that master cylinder was sent back East to that guy in South Carolina all completely rebuilt, so was the clutch master." This was done just months ago, so who knows ? At any rate I think I’ll research bleeding the MC and see what happens. If no luck, Then off to a local mechanic .
Just bleed the brakes normally but it will very certainly not fix it. Freshly done is no guarantee unfortunately. Brand new cars can fail off the line.
Maybe a long shot but did you check for leaks? When you returned home was the reservoir full or empty? Perhaps one of the brake line connections or bleed nipples are loose. It doesn’t take much to lose pressure.
I would start by removing the output line from the master and putting in a bleeder screw. If you don’t get a hard high pedal then that’s where you need to start. I suggest a NEW master cylinder. If that shows good then do the same with the output from the booster. Work your way down the line.
Thanks Gentlemen . I did not really take note of the brake fluid level, just unscrewed the cap, looked in and verified that there was fluid inside. So I will proceed down the line from the MC. when I have a bleeder screw in the output from the MC should, I have that bleeder open with a tube to catch the fluid or should that be closed ?
Closed, see if you get a hard pedal. Good idea to narrow things down.
Make sure nothing gets on the paint, tin foil, towels…
Many many years ago I had a Sunbeam Rapier that had a worn out master cylinder.
If you pushed the pedal hard the brakes worked fine because the seals were pushed against the cylinder walls and sealed, but if you pushed the brake pedal gently the fluid just flowed past the seals, the pedal went to the floor without any effect.
Is this how yours is?
James please don’t take this the wrong way, but if your understanding of brakes is a bit sketchy, can I suggest that you find a knowledgeable local mechanic who is good with classic cars and get them to address the problem?
Most of classic car repair responds well to tinkering punctuated with cups of tea, but brakes are mission critical and need to work. Especially in a 60 year old car with no airbags.
It’s likely that the fix for your problem is simple and won’t break the bank.
To digress into hyperbole, my experience with buying classic cars is that they have always just been serviced/restored/rebuilt/pick a verb by an acknowledged/legendary expert in the field, and that there’s nothing to be done but drive.
The first thing I do when I buy a car is rebuild the entire braking system, even if it seems to work perfectly. I’ve been doing this since I was 17 and I’m experienced but know my limits. The last thing I want is to die/kill someone because I trusted things that I shouldn’t have.
Sorry for the rant.
Right!
I learned brakes on my own cars. I was very closely following all guidance and if something didn’t feel right the job wasn’t done. And while I had a concept of how it’s supposed to work I learned by doing.
Gentlemen, all opinions and comments are welcome. I am not experienced at all with mechanical things in general, although I did rebuild a 1972 Triumph Daytona at one point about 25 years ago, so I like tinkering and generally know when I’m in over my head - to call an expert. which is what I’ve done now. He suggested that I try bleeding the brakes myself but if that doesn’t work, he has some piece of equipment that will work wonders. sounded like a Gundson type of setup to me. Then, if that fails to cure the issue, he can figure out what is the appropriate cure. abowie : your comments are exactly in line with my thinking at this point…
Been thinking about my lack of brakes / no pressure in the brake MC. We have been making the assumption that there is brake fluid in the MC. Now realizing that this is only an assumption, It seems to me that the MC is filled via the detached fluid reservoir container simply by gravity. When looking closely at my brake lines I see that the outlet from the reservoir is lower than the input to the MC. Also, the brake line makes a huge dip coming out of the reservoir and then a steep climb back to the MC. I am wondering if my issue is simply that the MC does not fill with fluid. That would surely explain the lack of any brake pedal pressure. I am thinking to buy the EEzibleed kit from Gunson and put some pressure on that reservoir and see what happens.
There is a one way valve on the end of the MC piston that allows fluid to be sucked into the MC when the piston moves back. This is an active process and so shouldn’t rely on gravity so probably isn’t your problem. Under normal circumstances, with the brakes working correctly, there is no requirement for additional fluid so the level in the reservoir doesn’t move.
Having said that there is no harm in trying positive pressure bleeding. If for some reason there is no fluid in the MC, the piston can stick in the forward position and not move at all when you push the pedal down.
Andrew, thanks for that information. Makes sense of course. So much for my simple solution idea.
Just noting your remote reservoir. Have a good look at the connecting hose - it must be a particular variety. My XJ6 has a remote reservoir as well and in my ignorance I fitted a hose compatible with oil/fuel. Over a year or so the hose delaminated internally to a point where the hose was occluded, denying movement of fluid. The early symptom was a pedal near the floor after a spell of freeway driving. My local brake specialist provided the correct hose, with no natural rubber, which I fitted up and then bled the system. Sorry, don’t recall the trade name. The exhausted brake fluid was rather black with fine rubber particles. The new hose did the trick and the car now brakes with full efficiency. Perhaps pull the hose and check the bore? FWIW.
My connection hose is actually a small diameter metal tube. However it does have a “kink” in it at the bottom of its “U” shape before the fluid begins its upwards journey to the MC. I have wondered if this “kink” ( it looks to me like it doesn’t close the tube entirely, but it certainly does reduce the I.D. of the tube ) is maybe keeping the MC from filling up from the remote reservoir via the suction that Andrew informed me of. Perhaps the pressurized bleed kit will push fluid into the MC and solve my issue ? And Perhaps I’ll win the Mega Millions lottery…