A long time ago i was reading about master cylinders and rear disc conversions and such. All of the rear disc convos i have seen just simply replace the rears. But i had a thought: Since our cars have factory rear drums then our master cylinders must have metering valves( a valve that engages the rears first since drum brakes fully retract when not engaged) so does that mean that cars w/ rear disc convos, when they hit the brakes actually engage the rears first? isn't this bad for braking and on pad wear,......?? i'am just curious
"Official Jewish J-Body"
Machzel08 wrote:A long time ago i was reading about master cylinders and rear disc conversions and such. All of the rear disc convos i have seen just simply replace the rears. But i had a thought: Since our cars have factory rear drums then our master cylinders must have metering valves( a valve that engages the rears first since drum brakes fully retract when not engaged) so does that mean that cars w/ rear disc convos, when they hit the brakes actually engage the rears first? isn't this bad for braking and on pad wear,......?? i'am just curious
since the fronts do the large majority of the force in braking, dont see where even if the rears engage first its gonna be an issue.
thats what i thought but i figured i would ask
"Official Jewish J-Body"
Actually, it is an issue. Slamming on the brakes a couple times this winter locked up my rear discs for a second before abs starts to kick in. I have to look into getting a proportioning valve before fall so it doesn't happen again. On dry and rain covered pavement, it's not a big deal. Ice and snow, the car really starts to act differently.
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never seen it happen on baer brakes, thats what tempted me to get em.
who;s neufang racing?
Dam-it Muffins (Event) wrote:who;s neufang racing?
You talking about Andrew? I think he's the one who did a rear disc swap using grand am calipers and redrilled corola rotors.
ahh didnt know he went corporate
Good, maybe finally I can get some plans on those rear disc plates
He didn't go corporate. I just doctored up the name of the brakes so that it looks good on a spec sheet
The difference between the Baer system and the Newfang outfit is that the Baer stuff is friggin huge when compared to one another. Correct me if I'm wrong but aren't the Baer brakes two piston? If so, there's a lot more volume in there for fluid to go. If no proportioning is done to the system, the Baer brakes should engage normally like the drums because of this. I never did a test but I can almost guarantee the volume in the cylinder of the newfang system is smaller than the volume in the stock drums.
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newfangs system looked perfect. Pute, is he still not responding to emails about the system? I saw him at the bash and he said he would send me some plans for the brackets if I emailed him. I emailed him a couple times and got no response.
00+ has proportioning valves already
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but we arent talking about proportioning valve(it just gives less pressure to the rear) the issue is that the metering valve puts pressure to the rears first
"Official Jewish J-Body"
Mr. Pute, have you had any of the issues associated with those rear calipers Andrew threw on? Because i've been warned by SEVERAL people to avoid using them, this could just be from past experience, but i dont want them to fall off from use
1998 Chevrolet Cavalier
5-spd
Zach, keep emailing him. He's slow to respond sometimes.
John Lenko wrote:00+ has proportioning valves already
Any way to mess with the proportion Lenko?
z22sTyLeS wrote:Mr. Pute, have you had any of the issues associated with those rear calipers Andrew threw on? Because i've been warned by SEVERAL people to avoid using them, this could just be from past experience, but i dont want them to fall off from use
Nothing except for the proportioning issue.
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hmmm... now i thought that there was a holding spring in the drum kept the shoes from expanding until pressure gets up to 130lbs. (which is nothing on a brake line) I have the ssbc kit. the only complaint(s) i have are:
1. need better springs on the e-brake cable. Lokar has them.
2. longer bolts on the wheel bearings. Used Grade 8 10mm-1.50 x 50mm (incase you were wondering)
3. you will need stiffer springs in the rear, as you have just added a considerabe amount of unspring weight. well don't "need" but good to have.
CAR GODS MADE THE 1.6 SOHC TO MAKE US 2.2 OHV GUYS FEEL BETTER.
Dam-it Muffins (Event) wrote:never seen it happen on baer brakes, thats what tempted me to get em.
actually, wild weasel has made it very clear in some of his old posts that he does think he feels the rears engage just a hair faster than the fronts (which i think prompted him to go "testing" on the highway lol) but he said that he was doing a lot of research into it.......
you all should ask weasy boutdis.....
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- Sold my beloved J in April 2010 -
Back when I first put my brakes on I thought I might have an issue with a residual valve effect in the back. None of my research found anything indicating whether any such thing was implemented in our braking system though.
In the end, I found out that a misadjustment of the parking brake cable was causing my rear brakes to drag. That was the source of the issue.
If there is any sort of metering valve in the system (which I never found documentation of) then I haven't found the effect to be noticable.
As far as proportioning goes... the ABS system on the newer cars (I think 00+ but I'm not sure) actually plays an active role in the proportioning and will prevent the rear brakes from getting too much pressure.
Wild weasel what did you do with the ebrake? Did you just let a little slack out of the rear cable by moving the clamp? I did the swap about 8000 miles ago and have been noticing more brake dust on the rear wheels. However, now I have a squeal when I'm off the brakes, so I'm thinking I ate down the pad. Haven't had time to pull off the wheel yet to confirm. Seems to be the right rear.
Also, off topic but - did you ever roll your rear quarters? Did that that stop the tire rubbing you were getting?
I solved my tire cutting issues by raising the car up a bit so even when fully compressed the suspension won't allow the tire to reach the front of the fender where it was making contact.
For the ebrake cable... I actually didn't have the new spring stop installed at first. You HAVE to put that on and you have to get that spring compressed down to 6" when slack. When the handle is pulled up, that spring should be pretty much completely bound. The springs on the calipers just aren't nearly strong enough to put the slack back in the cable when the handle is put down.
i thought the same thing at first, but it was just the fact that i had NEW pads, rotors, and freshly bled lines, when i resurfaced the fronts and got new pads it felt about equal.
CAR GODS MADE THE 1.6 SOHC TO MAKE US 2.2 OHV GUYS FEEL BETTER.
Wild Weasel wrote:In the end, I found out that a misadjustment of the parking brake cable was causing my rear brakes to drag. That was the source of the issue.
I was thinking that too with my setup. However, I completely disconnected the e-brake cable this past winter to see if it would still happen. Sure enough, the rears locked up before the fronts did.
Wild Weasel wrote:As far as proportioning goes... the ABS system on the newer cars (I think 00+ but I'm not sure) actually plays an active role in the proportioning and will prevent the rear brakes from getting too much pressure.
That doesn't make sense. Why would the ABS be in control of proportioning when ABS only kicks on when a corner locks up?
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My issue wasn't with the rear wheels locking up before the front ones. My issue was with the rear brakes lightly dragging and basically generating a whole lot more dust than the front ones.
As for the proportioning being handled by the ABS system... Just because you don't feel it activating the way we normally think of ABS activating doesn't mean it's not doing anything at all.
I'm almost tempted (if i wasn't broke) to get the rear discs even if their are issues..
my drums are always out of adjustment and are basically useless. original pads on my drums after 100k kms and still 3/4 of the pad left
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Just because there's lots of material left on those shoes doesn't mean they shouldn't be changed. With that many km's on them, they've likely been glazed over and provide almost no friction... and thus, almost no wear. So they'll last forever but not do squat to help with stopping.
how would sombody fix the porportioning issue? swap in a master cylinder from a 4wheel disc equipped car, or what? i'll be running a custom rear disc setup that a few have heard of, and i want to be able to change the braking from say 80% front 20% out back
1998 Chevrolet Cavalier
5-spd
