I bought the car in July of 2024 and, even though the records are extensive, I don't see in them when the brake fluid was last changed; may well be more than two years ago. It currently reads 1% moisture so presumably still ok, but I'm planning to replace it anyway to have a known age in the records for future reference.

Curious to know if others strictly adhere to the every-two-years replacement interval as recommended by Jaguar or if you just monitor the moisture content and replace when it approaches 2%?

 

I neither change it regularly nor monitor the moisture level. But that's not a recommendation!

 

The last Maintenance Checklist I have that was issued by Jaguar is the 2000MY.
We were required to fill this out for service records and fill in the customers PASSPORT TO SERVICE pamphlet.

No filled in form and the mechanic would likely be 'back-flagged' and the payment deducted from the paycheck.
The dealer would also lose reimbursement from Jaguar.

There are probably later MY forms but after 2 decades I cannot find any in my info.

 

So yes...every 2 years or more if your so inclined. Easy to do with the right tools. Honestly the hardest part is jacking the damn car up on all fours. My question is...was/is there a need to bleed the ABS?

 

Most car seem to be OK with a standard flush but it is easier if you don't get air into the ABS block.
Wrt frequency, remember that there are corrosion inhibitors in the brake fluid which get used up. Change every 2-3 years is a good investment of a little time and cheap fluid in a comparatively expensive system.

 

I was debating this too, but I haven't seen it done in any of the how-to videos I've come across, so I think it's not common to do it.

 

I can’t trust the moisture meters to be accurate down to 1.0% more or less. Refilling the system every 2 yrs from a previously unopened container is just prudent, although maybe not absolutely essential.


Z

 

Each time I change pads or discs I pump though a few hundred ml on each of the wheels I'm working on.

 

I would hazard a guess that at least 50% of all 10 year old cars on the road still have the original fluid and can still generally stop fine. Just bleed it every few years or if if feels spongy. Moisture meters seem like overkill for a non-tracked/raced car.

 

DOT 4 LV fluid is recommended. Its hydroscopic. Flushing every two years is recommended to maintain braking performance and help prevent corrosion in the system.

I raise the whole car, but It can be done with only one wheel up in the air at a time.

HTH, Dave

 

Every two years not overkill. I’ve seen many brake lines rusted from the inside out due to moisture in the brake fluid. It’s one of the simplest maintenance tasks to accomplish. So why not expend a little effort and $20 for a liter of quality DOT 4 or DOT 5.1 ( not to be confused with DOT 5.0 !!)

Z

 

Got it done over the weekend.
Tried with

this

this

vacuum system at first, didn't work for me at all, just sucked in air over the nipple threads. Didn't want to run out to get a pressure-fill system, so recruited a helper and did it the old-fashioned way, with brake pedal pumping. I ended up using almost exactly 1L of fluid.
Also measured the moisture content of the new fluid with my pen tester. It read 1%, same as the old fluid

Agree it's a simple task, but I'm clumsy and somehow seem to always spill liquids, therefore terrified that I'll spill or drip brake fluid on the brake calipers (the XKR Brembos have very nice powder coating on them!), or on the left wing while draining/filling the reservoir. I probably had 15 rags and blankets spread over the body and in the engine bay. Not a job I want to do more than necessary if I can avoid it!

 

if your new fluid was from a new and unopened container then I believe your moisture pen is
not working correctly. I always get less than 0.01% moisture from a new source

hah ! Can’t tell you how many times I’ve kicked over an antifreeze container while sucking antifreeze out of the expansion tank !

 

Okay, try a little thought experiment. Suck all the brake fluid out of the reservoir and refill with fresh fluid. Check the moisture content. Moisture content should be <0.1%, right? What is the moisture content of the fluid in the lines and calipers that is doing the job the next time that you press on the brake pedal?

Flush all the fluid out on a regular basis. I recommend changing the hoses out at least every 10 years. Your car is likely 20-28 years old. Are you still running with the original tires? Of course not. Why would your brake with the original hoses?

Yeah, really, every 10 years. I've had my Lotus Esprit for 35 years, and I more or less have to do it. I've had the hoses fail too many times. Once, a hose burst coming UP out of an underground parking garage (Yeah, in Orlando). 2 minutes later, I would have been in I-4 traffic. Other times, I've had it where a brake will lock, but when I go to look at it in the next day, it is freed. My theory is that the inside of the hose scales off and acts as a one-way valve, holding pressure and releasing it overnight.

I don't understand why people buy these expensive performance cars, then don't treat them right. Do periodic maintenance to your car, and reduce the chances that it will let you down when you need it the most. They don't break down in the driveway, they break down when you are far from home, in a rush to get some place.

One of the next jobs in my garage is rebuilding calipers, new rotors and pads, and new hoses, and of course a complete brake flush.

 

Yeah, I mentioned the 1% reading of the new fluid tongue-in-cheek as I concluded my pen gauge is junk. Several people have weighed in supporting the two-year interval, I'll go with that.

Thanks for the reminder on the hoses, somehow it didn't occur to me to replace those while the wheels were off and the brakes bled. Looking through the threads, I don't see any recent postings on recommended hose suppliers. +10 year-old threads talk about stainless braided from Goodridge, but I only see those available on ebay, which doesn't exactly give me a warm fuzzy feeling. Looks like I need to do some research again.