| Written by steve kupper | |
| Sunday, 08 March 2009 | |
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Use DOT 3 brake fluid. Use only brake fluid that has not been
opened. Brake fluid absorbs moisture, moisture boils before brake fluid,
boiling water does not stop 2002s.
Three pints should be on hand to change out the brake and clutch systems.
Three methods discussed.
Gravity
1. Fill the reservoir, open the bleed screws and let the brake fluid leak everywhere overnight.
Old fashion way - need a partner or helper.
1. Protect the area around the reservoir, brake fluid removes paint, unpainted metal rusts.
2. Fill the reservoir with fresh brake fluid.
3
Start at the right rear. Get a big bottle with a hose to it. The hose
needs to be the size that will fit tightly over the bleeder screw. Here
is what I use.
The
bottom of the jug should have some fluid in it. Keep the tube submersed
in the old fluid to keep air from being sucked back into the system.
4. Put the closed end side of a 8mm or 7mm wrench on the bleeder screw then put the hose over the bleeder screw.
5. Ask your helper to get in the car, pump the brakes slowly five times and on the fifth time hold to the floor.
6.
While the brakes are held, quickly release the bleed screw a bit and
watch for bubbles. Quickly close (after counting one-thousand one one
thousand two) the bleeder screw and tell the helper they can release the
brake. Get this sequence absolutely correct. Pump, Hold, Release and
close the bleeder screw, then and only then, release the brake pedal.
7. Repeat the process until you do not see any bubbles. Use a good light near your work so you can see the bubbles.
8. Keep checking the level of fluid and top off as needed.
9. Repeat the process on the driver's side rear.
10. Now move to the passenger's side front. Bleed in the same manner in the sequence of Upper, Inner and Outer (UIO)
11. Move to the driver's side and bleed like the passenger's side front.
12. Always checking the level of fluid in the reservoir and topping off as needed.
Power Bleeder method.
1. Same as the old fashion method but you need a power bleeder and the helper can go fix dinner.
2. Fill the reservoir.
3. Attach the power bleeder to the reservoir and pump to 10-15 psi.
4.
Bleed as old fashion way, (no pumping the brake pedal with the power
bleeder) keeping an eye on pressure and fluid in the reservoir.
Note: some folks fill the bleeder with fluid, I do not.
I guess there is another way but I do not know how to do that. That method uses a vacuum tool like a Mighty Vac
Brake fluid is nasty stuff, clean up real good and through away the rags or wash them good before you reuse.
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Showing posts with label brakes. Show all posts
Showing posts with label brakes. Show all posts
Saturday, September 29, 2012
Bleeding the E21 Brakes
Saturday, May 26, 2012
Monday, April 9, 2012
e30 calipers on e21 323 trailing arms?
conversation on bfc regarding the upgrade on an upgrade...after an owner swaps out 320i trailing arms for the disc brake counter part from a 323i...an additional disc brake upgrade is possible...specifically, removing the 323i calipers, drilling out the threads, permitting the nuts, and bolts required for the e30 disc brakes...the following is a discussion on bfc...
e30 calipers on e21 323 trailing arms?
Does anyone have any specific information on
this swap? I've seen it posted like its a direct bolt on but the '89
325i calipers I have are very different from the stock 323i calipers.
They mount from different sides of the bracket. Has anyone actually
done this swap that can give input?
Thanks, Steve.
Thanks, Steve.
I haven't done it, but it's a matter of drilling out the threads on one side to allow for the different mounting position. jrcook
My 323 trailing arms are disassembled now. I will have to reinstall the
bearings, axles, hub, etc so I can see how everything lines up. But,
if the 325 caliper mounts the same as the 323, the caliper bracket will
need more than just drilling the threads out. It is machined to mount
on the opposite side. The side to mount like the 323 bracket is just
the rough casting and has a rib which is higher than the areas around
the mounting bolt holes that would prevent it from sitting flush. It
looks to me like the bracket will have to be machined flat for proper
mounting. Can anyone verify this? I will try to check all this this weekend if I can. Steve.
I just did this conversion took pictures to do a write up, I believe I have the pictures on my digital camera that is with me, but my notes are home and I'm away on business. Below is a link for reference, that I used. I believed my calipers were from an 87 e30, holes lined up perfectly, I also believed that I drilled holes out with 13/32 drill bit. I used my drill press with 3" roloc disc to grind the carrier down, this gave me a machined like finish. I also had to cut the back-plate were the piston goes. Final touch was I bought some UUC brake lines. I'll do a write up this weekend when I'm home, I'll have access to my notes for exact size. Also I'll see if I can send pictures in the mean time. dhlthr
Additionally, the E30 brake hoses work fine on the E21 and bolt right up. I have done this now to both of my E21 and feel its better way to go. The E30 brake calipers offer more options for rear brake pad compounds and general availability.
I used a 13/32" bit. I then screwed the carrier to a board jig that would keep it flat and used drill press and grinding disk to grind area flat. I test fitted with rotor on trailing arm a couple of times to make sure that I did not over grind. When I was happy that rotor was center of carrier I was close to .580 width.
Apparently, Rob at BavAuto says this swap is as easy as pie, and a great upgrade. All that's needed is you have to drill a little. jjgbmw323
I picked mine up from junkyard, was told they were from an 87 eta. Don't know if there is a difference, but I believe all e30 caliper carriers are the same and have a 2.25" bolt spacing which is what our trailing arms have. I bought a rebuild kit and rebuilt my calipers as well (cheap and easy). dhlthr
The teflon sleeves are the newest trend, I have seen them in clear and red but don't remember if they were for BMW. I don't know of anyone making the teflon coated for 323i because of the banjo bolt. I had a set of bavauto with the 323i calipers. dhlthr
I went to the bone yard today&picked up a few pairs of e30 rear calipers, went home & modified a pair&got them mounted. These really are a much better designed caliper than the e21. The pad surface area really isn't much bigger, but rather than being a rectangle, the pads a are shaped in a trapezoid, so the outside edge is much bigger (more torque where it's needed). I found that I didn't need to modify my backing plate at all as long as you modify the caliper correctly. Jester323
I can identify only one
style of rear caliper for e30's. All of the calipers checked have 2.25" inch mounting centers, from E30 323i calipers
to E30 325ic calipers (earliest and latest, best I know). All of the larger series cars and later rear calipers I've found had a 3'' inch mounting centers (E36, E28, E23, etc)...
Source - http://s37.photobucket.com/albums/e53/dhlthr/
Source - http://forums.bimmerforums.com/forum/showthread.php?t=966135&highlight=brake+cooling+ducts&page=5
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| the e21 323i rear brake caliper |
Monday, November 7, 2011
323i Rear Disk Brake Dis-Assembly (Part 2)
a divorce forced me to sell the house i have lived in for over 20 years, this all took place while during the dis-assembly of the 1977 e21 that my son and i drove home from california where the car was raised and lived it 'sheltered' life...in the mist of this dis-assembly as you can image i have cardboard boxes and plastic containers filled with bmw stuff...my son and i loaded the car onto a car hauler several weeks ago and moved it to its new home...a 1 small one stall garage...in that move i have misplaced more than i've wanted too....but after some settling last week i jacked the car back up and placed the frame on jack stands in an attempt to finish the required work on the sub-frame, drive train, brakes, and wheel bearings...over the last few days i began to focus on the disc brakes from the newly restored 323i trailing arms...the motivation for restoring and upgrading to the 323i trailing arms was 2 fold...like the earlier model e21 the 323i has an upgraded braking system to accommodate the larger engines...in the case of the 323i another upgrade that is not commonly discussed is the increased size of the wheel bearings...this becomes important to tuners because many of us utilize larger wheels on our cars...and the jump from 13' wheels to 15" wheels in theory and practically increase the pressures applied to the wheel bearings as you can imagine..i replaced the wheel bearings, grease seals, and associated parts on my 323i trailing arms...the pictures below are of the 323i disc brakes...(but just for the record, i am of the opinon that wheel bearing increases are NOT a reason to upgrade to 323i trailing arms...the rear disc brakes are however are a good reason if you don't want to weld in the appropriate plate/brackets to hold disc brakes...
The picture above is a rear 323i disc brake that came with the 323i trailing arms i bought...these brakes are in reasonably good condition as you can see in the pictures...notice that the rubber piston seals are intact and still in good working order and could have been installed without replacement but while they are off of the car it makes sense to restore them...
if you look closely at the brake caliper in the picture above you may notice that the retaining spring that holds the 2 halves together has been broken off...this happened as i attempted to remove the clip...i broke 2 tapered punches trying to free the spring...usually these springs just slide into the holes and are held in place by the spring's pressure...this one was a BEAR...
...in the picture above you can see the backside of the caliper with the broken spring still in place...
...the caliper was taken apart...and as you can see...that's the first broken punch tip at the center!!!
...in my opinion, one of the most important aspects to rebuilding disc brakes is the condition of the brake piston, and the walls of the sleeve...in the case of this brake the piston is smooth, no scaring or scoring of either the piston walls, or the piston itself...for my purposes that means this brake is rebuildable and not scrap...
...as you can see...the 35 yrs or so of service has allowed sentiment, and crud to settle in the closed system...i am in the truest sense of the word only a weekend mechanic and my "poor boy" ways learned as a kid in my dad's garage never took things like this seriously...for me this was a lesson in maintenance...the interior walls of this disc brake will NOT be honed because the walls are in perfect condition as is the piston...with the new seal kit the rubber piston ring will seal nicely and fit/slide smoothly...
...this is the best picture i could get of the interior walls of the sleeve...notice the retention ring, the rubber seals have been removed...crud is still in place however!
...after dis-assembly and cleaning the caliper with solvents, a wire brush, and a wire wheel in preparation for paint, i fit the brake back onto the trailing arm bracket. notice the NOS dust shield...new parts are sexy!
...if you look at this picture closely...you'll see this was my best attempt to fix the retaining spring stuck inside the brake caliper...i thought i would be "smart" and put the caliper in my drill press, squared, and level i tried drilling out the spring fragment...what i DID NOT anticipate was the differences in metal hardness...when i tried drilling the spring out the drill bit shifted and the result was that the drill bit slid into the caliper avoiding the harder spring steel...thus creating another hole in the caliper!!! ugh...unanticipated result for sure...but confirmed i'm only an amateur...
...this picture illustrates the "second" hole that resulted...i am anticipating using that hole to install the new retaining clip...it will be tilted off angle somewhat and certainly not what i wanted...but...
...cleaned and painted...
...second half of the caliper cleaned and painted...is it my imagination or do those holes seem to stick out in this picture...lol...
..what is pictured above is the rubber boot included in the 323i rear disc brakes rebuild kit...specifically, the rubber seal inside the brake sleeve, the piston, the rubber boot, and the outer snap ring protecting the piston and associated parts for being contaminated with dirt and grit which eventually will deteriorate the inner rubber seal between the piston inside the brake...
...believe it or not getting this rubber boot to fit correctly down into the piston was the most difficult aspect of this assembly...
...finally, the boot fitted down inside the piston and the snap ring is installed...
...the pads were fitted to the brake pad mounting pins (seen unseated)...
...ok, the first one is finished...but, as you can see i didn't have the vent/airator but its on order.
Monday, October 3, 2011
brake performance
Well that depends on what sort of brake "performance" you're talking about.
Stopping distance: Depends mostly on your tires. Brake upgrades won't change this much.
Fade resistance: Depends partly on rotor cooling and partly on pad compound. Vented rotors and good pads will help with this. Calipers have no effect.
Pedal feel: The pedal will take less force but longer travel to achieve the same brake torque with the Volvos compared to the 323i calipers. You may want to change the master cylinder to a larger bore to make the travel shorter again. Once you do that there is probably no difference in the feel.
The size of the pad area only effects how long it takes to wear the pads out. It does not effect the braking torque and probably has minimal effect on the feel.
Basically you need vented rotors, good pads, and good fluid. Caliper choice is 1/10 as important as any one of those. Front 323i calipers are identical to '77 320i calipers, and their only advantage is that you are able to run a vented rotor.
Stopping distance: Depends mostly on your tires. Brake upgrades won't change this much.
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| 1977 Frnt Calipers |
Pedal feel: The pedal will take less force but longer travel to achieve the same brake torque with the Volvos compared to the 323i calipers. You may want to change the master cylinder to a larger bore to make the travel shorter again. Once you do that there is probably no difference in the feel.
The size of the pad area only effects how long it takes to wear the pads out. It does not effect the braking torque and probably has minimal effect on the feel.
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| http://www.massivebrakes.com/kits/e21/front/300/32/ |
Braking torque can be a consideration, however, how much does brake torque matter once they've been locked up if you don't have ABS None. Once you start running bigger&stickier tires, it becomes harder to lock the tires up, so then more brake torque is needed. Until you get to that point, bigger brakes will just have a longer life and stay cooler (definitely advantages to both of those) and will likely have more un-sprung weight (not so much of an advantage).
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| 1977 Front Calipers |
i do know that with stock vented rotors, calipers, hawk hp plus pads and ATE fluid, i can overpower the summer tires i'm running.
Pads: Hawk hps brake pads are about as good as it gets.
Torque is a measure of the turning force on an object and is greatly influenced by the length of the lever. the longer the lever the greater the mechanical advantage. therefore a bigger diameter rotor has more torque. i really don't believe pad size makes much difference with torque. (larger pads = longevity!)Wilwoods brake calipers usually have a larger pistons (and several sizes are available) which does increase brake torque for a given line pressure, but you can always just press harder on the pedal instead. Wilwoods are also much lighter which is kind of a big deal since they are unspung weight (attached to the movable part of the suspension). But yeah, any brake upgrade that uses the same rotors is mostly for cosmetics/bragging.
there is a good discussion over on the forums regarding the upgraded girling calipers...its worth reading...it can be found here...
http://forums.bimmerforums.com/forum/showthread.php?t=308282
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