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What’s needed/how-to drain brake system and refill?

2K views 22 replies 9 participants last post by  o2batsea 
#1 ·
I tried to search to little avail.
I want to drain the brake system as I suspect it has been filled with DOT 3 vs DOT 4.

What tools will I need to make this a successful job? I have the DOT 4 fluid but unsure of any special tools, or other things to replace while the system is drained.

thanks for sharing your input, experience, etc.

I hope to be a contributor as I learn more about the vehicle.

I have a 1995 110 ROW
 
#3 ·
You don’t need to change it. DOT 3 is fine.

If you do want to flush it a Motive pressure bleeder is the nicest way.
any idea which specific one here? There are about 37 options…

 
#4 · (Edited)
Don't overthink it. Get a big syringe. Suck out as much fluid from the reservoir as you can. Fill with new.
You're then just bleeding the brakes like normal. If you have a helper who can pump the pedal for you, do that. You need a box end wrench for the bleed nipples (10 or 11mm, can't recall) a bit of 3/16 clear plastic hose and an empty Deer Park water bottle. I poke a hole in the cap so the hose goes thru the cap, preventing spills.
Start at left rear wheel. Stick the plastic hose on the end of the bleed nipple, and the other end in the water bottle. Have friend push down on pedal. Crack bleed nipple to let pressure out. Close bleed nipple. Tell friend to let up on pedal. Repeat about ten times or until fluid runs clear. Don't over tighten the nipple when you're done on that wheel.
Move to right rear and do this again. Then right front then left front.
 
#7 ·
Dot 4 is compatible with Dot 3. Dot 4 is made for an ABS system. You don't need to change anything. If you feel the need. As Bill mentioned, suck out the reservoir with a syringe or turkey baster for that matter of the offending Dot 3. Then just add Dot 4 and bleed the calipers. Don't overthink it.
 
#14 ·
i did some additional reading and now concerned my brake fluid selection is not good. I selected a synthetic brake fluid but now I read that isn’t ideal. I have synthetic DOT 4 on hand but now rethinking I should be using a mineral oil to avoid damaging seals, etc.

What’s the word on the correct brake fluid to be used? What is highly recommended?
 
#8 ·
land rover recommends dot 4, you can upgrade from Dot 3 To Dot 4 But cannot down grade from 4 to 3, I am not a chemist but it has to do with formulation, heat and water absorption and metallurgic reaction in relation to disc brakes and rubber properties and corrosion resistance. also you cannot mix fluids, in order to replace one for the other, you must drain and flush all residual of current fluid and fill your choice.
top of reservoir or filler cap should suggest what fluid to use as recommended by factory, do not use synthetic blends.

and a personal suggestion, brakes is one of a few components where it is not wise to be frugal.
 
#10 ·
If you don't have a friend to push the pedal, use a length of wood maybe a 2x2 or the like. You have to get the length based on how far from the pedal to the seat base where you're gonna jam the end. So, you push the pedal until it won't go any more, jam your wooden helper between the pedal and the seat, then go open and close the brake nipple. Repeat until done or you're out of breath whichever comes first.

I have the easy bleed kit which I have never used, it's too fussy.
 
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#12 ·
I will be working solo so tricks and tools are great for me to ponder.




Using the 2x4 helper I can leave the brake depressed and move from corner to corner without touching the “helper” again, correct?

Simply top off the reservoir as I flush, correct?
 
#11 ·
I like my motive power bleeder and my vacuum bleeder. But a simple hose and friend serves me well. Heck, ive even gravity bled brakes. So many different ways, with special tools or with no tools— end results are the same...
 
#16 ·
Can you get non-synthetic brake fluid anymore?
The DOT rating is like the API rating on your engine oil. I just means that it meets specifications for all passenger car braking systems. It doesn't mean that using DOT 3 will eat up your seals or vise versa. I personally prefer the Castrol DOT4 when I can find it. However, you can use any brand even the store brands cz they get it from the major manufacturers and put it in their own bottles.
Using pure silicone fluid (DOT5) in a system with DOT 3/4 is a no no. Stay away from that stuff. I tried it once and that was enough for me.
 
#20 ·
You start with the wheel furthest away from the master cylinder (measured by length of brake tubing) and work toward the closest. The side you steer from isn't critical.
I'll take a guess that it's going to be the left rear that you start with, then right rear, left front, then finish with right front.
I would say you need one big bottle of brake fluid, or two small.
Depending on the age of the braking system, you may want to have a few extra bleed screws on hand.
 
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