How much Brake Fluid will I need?

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676
Location
TX south plains
Going to replace the rear pads and rotors on my 1994 Jag XJS soon. Finally have all the parts in my hot little hands. Never done brake work before so I'm reading up and trying to make sure I get everything right. Have one simple question: How much of the brake fluid will I need? I bought one 32 oz bottle of BreakBest dot 4 for the process - is that enough to bleed the entire system?
 
Yeah, that should be more than enough. Good you bought new too. I always recommend buying a new sealed bottle of brake fluid so there isn't moisture from storage once opened. I have never serviced a Jaguar in my life, but assuming the master cylinder is on the driver side, when you bleed, start bleeding from the caliper farthest from the master cylinder, i.e. assuming the master cyl is on the driver side, start bleeding from the rear passenger caliper, then rear driver side, then front passenger side, then front driver side in that order. Good luck!
 
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cadfaeltex

Thread starter
Messages
676
Location
TX south plains
I bought new and will not keep it long after I'm done with it. You are correct on the location of the Master cylinder and the bleed order. The unique challenge with this particular Jag is the ABS system. Since it has an accumulator attached to the rear wheels you have to use the ignition on to bleed them properly.
 
Messages
19,528
Location
Lake Forest, CA
To use the whole 32oz bottle, you want to use 1/3 bottle for each rear wheel and 1/6 bottle for each front wheel. After bleeding is done you should have 2-3oz remain in the bottle to top-off the reservoir to slightly above max.
 

cadfaeltex

Thread starter
Messages
676
Location
TX south plains
On reading on a jag centered forum, it said I would need 3 quarts to do the whole system. Does that sound right? I would like to get all the old 'unknown quantity' fluid out.
 
Messages
36,528
Location
ME
Do the geometry of 3/16" round brake line by however long it is. 3 quarts is way too much. I bet your MC reservoir holds about 5 ounces; mine always bleed with about half that capacity per wheel. IE I can top off the cylinder then bleed without it going totally dry, a bad-thing.
 
Messages
19,528
Location
Lake Forest, CA
How are you going to bleed the brake system ? Gravity or 2-man or pressure bleeder or vacuum or ? I used only 1 quart to bleed either one of my cars, actually I could use less than a quart for S2000, but I let my fluid extractor ran a little longer than needed for all 4 corners to use the full quart.
 
Messages
14,505
Location
Top of Virginia
Check with Jaguar to make sure you bleed the wheels in the right order. You often go from furthest from the master cylinder to closest, but with both of our Hondas, you go from LF to RF to RR to LR. So just make sure of the correct order before you begin. I bled our Acura's brakes this weekend, and was my first time doing it (2-man method, using the brake pedal). It was a piece of cake really. I used almost two of the small 6 or 8 oz bottles.
 
Messages
19,528
Location
Lake Forest, CA
I think it doesn't matter which order you bleed your brake system, just follow that order for all systems. The reason is if you do the farthest to the shortest and you just finished the driver rear wheel, then next is passenger wheel, there is no way you can skip 1 wheel because you think that you did that wheel.
 

Kestas

Staff member
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13,983
Location
The Motor City
For reference, Mercedes recommends bleeding 250 ml from each corner during the fluid exchange procedure. I believe HTSS_TR's recommendation (1/3 for rear, 1/6 for front) would be more appropriate because of the length difference in brake lines. I think Mercedes is just trying to keep it simple for the average person.
 
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