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View Full Version : prelude caliper swap = worse braking than stock


timmy0tool
06-11-2005, 02:24 AM
i just upgraded to prelude calipers and rotors. however my braking has gotten worse compared to my stock setup. reason being is that my pedal feels extremely spongy! i bled the system TWICE and still no improvement. i'm just out of ideas now.

history/facts:
- vtec prelude calipers and rotors
- during bleeding when the pedal was being pumped, the caliper would pulsate a bit with each pump (is this normal?)
- my brake pedal tends to sink only on hot days (of course a sign of a bad mc)
- during swap, there was a lot of fluid loss but i'm pretty sure i've gotten all the air out of the lines
- i used an old bottle of DOT3 brake fluid (maybe 3 months old)
- the calipers were used but fairly in good condition (no rust in the piston, springs, seals, etc.)
- i used the old brake pads from the used caliper (still has a lot of meat left)
- pads are getting full contact on the rotors
- pads are shimmed
- i bled the system with the car off using the following technique:
pump pedal-hold-loosen the bleeder valve-look for air in the line-tighten valve and repeat if necessary
- i only bled the front calipers (if that matters)

HELP me diagnose my squishy brake pedal and overall crappy braking! i'm super afraid to drive her. TIA!

clarksterdotcom
06-11-2005, 02:31 AM
hey man...werent you still using the stock LX porp. valve?...maybe you should upgrade to the integra 40/40...

but for me on my stock braking system i know that my BMC is going so i have a new one sitting in my room waiting for me to install it. but i am going to go rear disc conv. so i can do it all at once.

ACCORDing2R
06-11-2005, 02:40 AM
I have prelude rotors/calipers... and the braking is far superior than stock.
My concern is your used pads... I don't care how much meet it looks like they have, when you do this kind of upgrade, go brand new pads! Check your master cylinder too, maybe it suddenly went when it sensed the prelude brakes. :shrug:

timmy0tool
06-11-2005, 02:58 AM
yeah i know my MC is already bad due to the pedal sinking, but that only happens when it's super hot out (90+). it sinks slowly though. i'm still considering the 40/40.

what trim do you have ACCORDing2R? did you change your MC? i have an LX so my MC is made for drums. i converted to disc awhile ago. does a prelude MC bolt into our cars? i'll look into the pads but why the spongy pedal?

i hope the LX braking system with a rear disc conversion and stock prop valve is adequate enough for the lude calipers.

BustedLX
06-11-2005, 09:08 AM
Change your MC as soon as you can that's most likely the source of the problem. Remember to bench bleed the new one before you hook the lines up to it.

Oh yeah and say "hi" to my engine in ACCORDing2R's sig, lol I love that.

timmy0tool
06-11-2005, 01:12 PM
sounds like i have lots to do. can i used a prelude MC? if so what year? i'm not too familiar with bench bleeding. how do i do it?

does it matter that i mixed different brands of brake fluid? one was DOT 4 and the other was DOT3, both different brands too.

xScott
06-11-2005, 01:44 PM
Also, dont use fluid that has been sitting, or came in a plastic bottle. Air can seep through the plastic. Only use stuff in new, metal bottles.

timmy0tool
06-11-2005, 02:42 PM
thanks for the rely guys! can an air pocket travel from the front to the rear? remember i only bled the front.

now what's the best way to flush the system? just bleed bleed bleed then no fluid?

SilverCel
06-11-2005, 02:49 PM
Yes, that was what i was going to say.

you must bleed from the far corner of your MC, then the other side, then do a few pumps and redo the far corner, then do the other side, then do the front farthest, then go back to the back other side, and do a few pumps and bleed, then do the front side again, then do the side w/ the MC, then go back and bleed the other front side, then do the front side w/ the MC again.

thats how the honda tech taught me how to do it.

most reliable way and only way he'd let me do my brakes.

aero
06-11-2005, 03:35 PM
I would also say try the master cyl. but I have had the same kind of problem.. only changing pads, and someone mentioned that they had the same problem, and there was stuff stuck in the prop valve.

I am going to be redoing pretty much the whole system again, and If I wanted to completely flush the system, and then add the 600deg. fluid, would I follow the flushing procedure above? Since Im sure you dont want regular fluid mixing with the hi-temp stuff.

phatdoughnut
06-11-2005, 04:01 PM
You did the rotor over hub too? coolness i did mine like 2-3 wees ago and i was gona use my jdm prelud e MC but the lines come out on the opisite side, bummer. i do have the lude booster that i am going to be using w00t!

uh 92-95 SIvtec MC, go to your local auto parts store cheaper that way, anywhere on the net they want more than 160 for it plu shipping ***ness..... mine feels a little sponge but once its gone ill get a new one..

timmy0tool
06-11-2005, 05:14 PM
Yes, that was what i was going to say.

you must bleed from the far corner of your MC, then the other side, then do a few pumps and redo the far corner, then do the other side, then do the front farthest, then go back to the back other side, and do a few pumps and bleed, then do the front side again, then do the side w/ the MC, then go back and bleed the other front side, then do the front side w/ the MC again.

thats how the honda tech taught me how to do it.

most reliable way and only way he'd let me do my brakes.
yeah that's how i bleed my system. my question is how do you flush out the old fluid?

phatdoughnut: you can use an EG si MC?!

phatdoughnut
06-11-2005, 07:56 PM
nah dude, you asked what year prelude, so i said the SIvtec 92-95 which in turn i thought you would understand which one.

pretty much any EX one is best, check this out i did a little reasearch online and they are hella expensive, go to your local auto parts store and get the Lude SIvtec one.


http://www.accordinglydone.com/forum/showthread.php?t=9932

arrozburner
06-12-2005, 02:59 AM
i used the the 93 prelude vtec MC when i did my swap...dropped right in and it only ran me about $75

SilverCel
06-12-2005, 05:21 AM
I used 2 bottles of dot 5 brake fluid to flush out my brake lines.

just kept bleeding and pouring and bleeding and pouring. mostly out from the rears to get most of it out.

but 2 bottles, you'll see what i did to my celica to get the dot 5 in there.


i see you guys have a similar setup avalible for your cars by upgrading to the vtec prelude things, but is it worth it?

it was found that the JDM celica GT4's came w/ dual piston brake calipers, but the upgrade of choice for them were the single piston because of the larger piston.

timmy0tool
06-12-2005, 05:53 PM
nah dude, you asked what year prelude, so i said the SIvtec 92-95 which in turn i thought you would understand which one.

pretty much any EX one is best, check this out i did a little reasearch online and they are hella expensive, go to your local auto parts store and get the Lude SIvtec one.


http://www.accordinglydone.com/forum/showthread.php?t=9932

duh! sorry for thinking that you meant a MC from an EG. i had that car in my mind recently. i'll try and get a lude vtec MC asap.

thanks for all the help!

timmy0tool
06-13-2005, 12:39 AM
one more thing!!!

for the lude vtec MC, should i go OEM or any aftermarket company will do? lastly, can the caliper pins cause my horrible braking? idk i just thought i'd ask too.

arrozburner
06-13-2005, 01:36 AM
i went aftermaket and its working great

timmy0tool
06-16-2005, 02:19 AM
update:

i flushed out my old brake fluid, replaced it with new fluid, and replaced my MC today using an LX piece (see why other MCs don't work here (http://www.cb7tuner.com/vbb/showthread.php?t=24322).) the problem still remains :angry: !

my pedal is still very mushy and low. my next thing to change is the proportional valve to a 40/40. do you guys think the used calipers can be causing this problem? the looked like they were in good condition (good piston seals, no rust in the piston, etc). the previous owner said they sat in the garage attached to the car for a year.

HELP!!!

phatdoughnut
06-16-2005, 12:43 PM
so did you switch to dot 5? i what does the EX MC look like exactly, can we get a pic? any way we can just seal off the second hole with Jb weld?

there has to be away around the ABS shit

owequitit
06-16-2005, 01:14 PM
Just a thought here, but if the calipers were bad, you would probably be losing fluid visibly. They only have the seal and the boot. If the seal goes bad, you will know it. Also, it seems to be a common symptom to have a mushy brake pedal, with the incorrect proportioning valve. I am still gathering the final parts to complete my VTEC swap, but I will keep you posted if I have the same problem or not.

timmy0tool
06-16-2005, 01:19 PM
i used fluid that "meets or exceeds DOT 3 and DOT4". it should work. the EX MC has one fitting LARGER than the other. you will need redo one fitting in order to make it work. that's all!

how to add a larger fitting is something i don't know how to do. i was thinking to just get another line with a larger fitting on there already but you will need to bend that line so it can travel down to the prop valve instead of the ABS unit (which we don't have).

phatdoughnut
06-16-2005, 01:35 PM
ah thats what people were telling me, about, you need to get a gun/pliers to flare out the fitting, we need pics for sure.

phatdoughnut
06-16-2005, 01:59 PM
well i know what i am going to do, i looked at my mc and the jdm lude one i have, there must not be much of a difference cause they look the same size.

this is what i am going to do, since i still have my clip, thank god my dad didnt trash it yet. i am gona take the lines(since its non abs, and the lines are backwards cause its RHD) and install the lude prop valve with lines and use my lude MC and booster i have now.. ill let you know how it feels.

my suggestion to you! is, if i can afford the down time, take off your lines and take them to auto parts store and have them flared and fitted to the lude Vtec mastercylidner. i doubt they will charge more than 15 bucks.

timmy0tool
06-20-2005, 04:32 PM
to flare the line is no problem. to obtain a larger fitting is. i don't know if the larger fitting is a standard size. i will be putting pictures up soon to show the size difference.

update:

i changed the prop valve to a 40/40 from a DA integra (90-93) non-abs. braking has restored to firm! the only difference i feel is that it only gets firm about midway as opposed to a quarter-way down as i depress the pedal. the car starts to slow down as soon as i depress the pedal though. at least my brakes work!

thank you all for helping me through my rough week. at least now i know a ton about my brakes and their design and function.

aero
06-20-2005, 04:46 PM
you wanna get rid of the stock prop valve? You have rear drums right? I think my prop valve might be clogged, so I want one that I can clean out, then swap quickly instead of taking one off, and then cleaning it.. then putting it back on.

I have the same problem as you, but I have stock calipers and everything.

arrozburner
06-20-2005, 04:47 PM
i was going to suggest making custom braking lines from stainless steel lines with prelude fitting for the MC and the accord for the other end

timmy0tool
06-21-2005, 10:56 AM
i was going to suggest making custom braking lines from stainless steel lines with prelude fitting for the MC and the accord for the other end
i was thinking the same thing but i needed my car running and i didn't want tackle something i wasn't prepared for and have little knowledge of. let's custom make a line then i'll get the lude MC. at least for now my brakes work once again!

timmy0tool
06-21-2005, 12:20 PM
the breakdown:

the stock DX/LX MC: both small fittings
http://im1.shutterfly.com/media/47b7cf27b3127ccec2d95acb243e00000010O00AatWLRs3buG IPbz4G/cC/f%3D0/ps%3D50/r%3D0/rx%3D550/ry%3D400/

the vtec prelude MC: big fitting, small fitting
http://im1.shutterfly.com/media/47b7cf27b3127ccec2d83e6304e800000010O00AatWLRs3buG IPbz4G/cC/f%3D0/ps%3D50/r%3D0/rx%3D550/ry%3D400/

notice the fitting closer to the flange is larger on the lude MC than in the stock MC. this is the reason that you cannot use the MC unless you get a larger fitting that fits.

timmy0tool
12-16-2008, 02:05 PM
^ pic above rehosted! hondafan81 i know you needed this!