Brake reservoir question
Discussion
How do you reduce or empty the front half of the brake master cylinder reservoir? It appears that the reservoir is divided between the front & rear systems, and I can drain or reduce the REAR of the reservoir, but don't see any way to drain & add to the FRONT half of the reservoir that supplies fluid to the front brakes? Is the rear half of the reservoir ( where the cap is...) also supply the front half?
I want to flush/change all the brake fluid, not just on the rear system....
Doug
I want to flush/change all the brake fluid, not just on the rear system....
Doug
Thxs! I assumed the front & Rear parts of the reservoir were internally connected, but wanted to be sure. I bled the rear of the reservoir by first using a large syringe and removed as much of the old fluid from the rear section so I could "start the bleed" with totally clean new fluid in the reservoir before I started the bleed at the rear bleeder valves.
Yesterday when I suctioned out the rear part of the reservoir, it just didn't seem to remove as much old fluid as I thought it would. Plus there is no way to "see" (visually...) how much old fluid was still remaining in the front section of the reservoir. Likely a small amount of the old fluid remined as I didn't remove "all" the old fluid to avoid getting any air into the intake ports on the top of the brake master cylinder bore.
Bottom line is that 99% the old fluid is out & the new 5.1 fluid is in and bled at all 4 wheels. it's been 3-4 years since that was done last....
Thxs again for your quick response so I could finish the job this morning!
Doug
Yesterday when I suctioned out the rear part of the reservoir, it just didn't seem to remove as much old fluid as I thought it would. Plus there is no way to "see" (visually...) how much old fluid was still remaining in the front section of the reservoir. Likely a small amount of the old fluid remined as I didn't remove "all" the old fluid to avoid getting any air into the intake ports on the top of the brake master cylinder bore.
Bottom line is that 99% the old fluid is out & the new 5.1 fluid is in and bled at all 4 wheels. it's been 3-4 years since that was done last....
Thxs again for your quick response so I could finish the job this morning!
Doug
When you bleed the system again, you basically keep pumping the pedal until you see the fluid run to a lighter colour.
But after 3-4 years, I wonder if you'll notice much difference if you have a leak-free system.
I know we have brake and clutch fluid intervals recommended, but unless you're driving it hard a lot, and the performance of the brakes is becoming poor, the fluid should be fine for a good few years - we don't change these fluids on modern daily cars so often.
And if your brakes are performing poorly, then yes a fluid change is a good place to start, but may not be the issue.
I also wonder why you've gone for Dot 5.1 - again unless you're racing and getting very hot brakes, Dot 4 is perfect.
In fact, Dot 5.1 has a higher propensity to absorb moisture, so will deteriorate quicker therefore require more frequent changes.
Apologies if you know all of this, if we were at the pub for a meet, we'd be having a chat, not reading posts on a forum!
But after 3-4 years, I wonder if you'll notice much difference if you have a leak-free system.
I know we have brake and clutch fluid intervals recommended, but unless you're driving it hard a lot, and the performance of the brakes is becoming poor, the fluid should be fine for a good few years - we don't change these fluids on modern daily cars so often.
And if your brakes are performing poorly, then yes a fluid change is a good place to start, but may not be the issue.
I also wonder why you've gone for Dot 5.1 - again unless you're racing and getting very hot brakes, Dot 4 is perfect.
In fact, Dot 5.1 has a higher propensity to absorb moisture, so will deteriorate quicker therefore require more frequent changes.
Apologies if you know all of this, if we were at the pub for a meet, we'd be having a chat, not reading posts on a forum!
Yes, Dot 4 and 5.1 are compatible, so no issue, just designed for different situations.
Also agree that having fading brakes is an absolute no-no, but do they suddenly go, or is it more gradual and you can accommodate for it by driving more slowly until you get home to assess why it's happening? For example, if it's a rapidly deteriorating situation, it's not because the brake fluid is old, something more immediate has happened (or you're on lap 14 of Silverstone and the whole car is shouting back at you).
I'm really not trying to tell anyone to be cavalier, I just wonder if we are influenced by marketing more than sense at times (and I work in marketing).
I also recognise that this really isn't the spirit of this thread, so I'll shut up now.
Also agree that having fading brakes is an absolute no-no, but do they suddenly go, or is it more gradual and you can accommodate for it by driving more slowly until you get home to assess why it's happening? For example, if it's a rapidly deteriorating situation, it's not because the brake fluid is old, something more immediate has happened (or you're on lap 14 of Silverstone and the whole car is shouting back at you).
I'm really not trying to tell anyone to be cavalier, I just wonder if we are influenced by marketing more than sense at times (and I work in marketing).
I also recognise that this really isn't the spirit of this thread, so I'll shut up now.
I retract my comments.
Common wisdom has been debunked by a bit of light research.
If the clutch/brake fluid is gathering moisture (as it is prone to doing), it can cause corrosion on the system.
Therefore changing it every two years is a good way to keep that at bay.
It’s a good job dot 4 isn’t expensive!
Common wisdom has been debunked by a bit of light research.
If the clutch/brake fluid is gathering moisture (as it is prone to doing), it can cause corrosion on the system.
Therefore changing it every two years is a good way to keep that at bay.
It’s a good job dot 4 isn’t expensive!
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