brake pedal

[2drSE-i]

Have you bled your brakes recently? A lot of mush can be created with air. Also, if your brake booster has been replaced, ever, then you have an adjustment nut for the pedal. Adjusting it will help take up a lot of pedal travel, not so much helping the mush feeling, but it will help.

I drove it for a week maybe without the brake booster, and I'm not a weak guy, but I COULD NOT stop the car as fast without the vacuum assist. It takes some pedal mashing, for sure. If anyone were thinking of doing a booster delete, I would suggest a very large master cylinder.

[2drSE-i]

Have you bled your brakes recently? A lot of mush can be created with air. Also, if your brake booster has been replaced, ever, then you have an adjustment nut for the pedal. Adjusting it will help take up a lot of pedal travel, not so much helping the mush feeling, but it will help.

I drove it for a week maybe without the brake booster, and I'm not a weak guy, but I COULD NOT stop the car as fast without the vacuum assist. It takes some pedal mashing, for sure. If anyone were thinking of doing a booster delete, I would suggest a very large master cylinder.

[Dr_Snooz]

What pad composition would prevent cementite build up and the dreaded front brake wobble at high speed? I've never owned a Honda that didn't do that. Bedding helps, but doesn't eliminate it. I think the OE spec pad composition is just too soft.

I agree with Ichi and Cygnus, by the way. If you're dissatisfied with Honda brakes, something is wrong with them. Get them fixed and you will be more than pleased. The feel, responsiveness and predictability of the factory set up is vastly superior to most other cars.

[DBMaster]

Wobble? You mean pedal pulsation, right? Mine started doing that, out of the blue, a number of years ago. I resolved it with the Brake-Tru on-car resurfacing kit. It was low-tech and very effective, but it is no longer made or available. I replaced my rotors at the last pad change because they had finally gotten down to less than 0.75" thickness. Within a few thousand miles the wobble was back. My only choice was to have the rotors resurfaced at a shop (NTB). It's been fine for several thousand miles now so I'm hoping. My mechanic told me that it may continue to return because the uneven rotor wear may be caused by lateral movement of the front wheel bearings even though they still feel good and tight.

[2oodoor]

...brake threads, gotta luv em

I believe wobble and pulsation are two different symptoms. You can have one without the other.
When I usually feel road speed wobble it's with rear discs but I can understand it could be with a rotor set on any axle.

I would first suspect contamination, one being tire shine products.

Also regarding brake (feel) I could feel two very distintive envioronments between any of the 3rd gen I've had and the 94 Civic I had or any I've driven.

Not that one is better than the other but the Civic definatley had a really light feel but powerfull low speed stopping. I think the booster and MC are different "specs "for lack of a better word.

[Warren 88 Accord]

my pedal doesnt feel like its pulsing even under harsh braking conditions there is no wobel even up to 100 mph but it just feels like i have to push down a long way before it starts to slow me down but i stil have a alot of travel left

[lostforawhile]

Have you bled your brakes recently? A lot of mush can be created with air. Also, if your brake booster has been replaced, ever, then you have an adjustment nut for the pedal. Adjusting it will help take up a lot of pedal travel, not so much helping the mush feeling, but it will help.

I drove it for a week maybe without the brake booster, and I'm not a weak guy, but I COULD NOT stop the car as fast without the vacuum assist. It takes some pedal mashing, for sure. If anyone were thinking of doing a booster delete, I would suggest a very large master cylinder.

the book shows an increase of over 150 feet with a failed power booster, the adjustment nut on the back of the booster has nothing to do with the pedal, it's to set the pushrod length right on the booster, if this isn't set right, the rear compensating ports in the MC will be blocked.

[lostforawhile]

Wobble? You mean pedal pulsation, right? Mine started doing that, out of the blue, a number of years ago. I resolved it with the Brake-Tru on-car resurfacing kit. It was low-tech and very effective, but it is no longer made or available. I replaced my rotors at the last pad change because they had finally gotten down to less than 0.75" thickness. Within a few thousand miles the wobble was back. My only choice was to have the rotors resurfaced at a shop (NTB). It's been fine for several thousand miles now so I'm hoping. My mechanic told me that it may continue to return because the uneven rotor wear may be caused by lateral movement of the front wheel bearings even though they still feel good and tight.

you can get brembo rotors for this car, even Honda uses them stock now, there really is a difference, it's all in the metallurgy of the rotor, a lot of big box store rotors are chinese and made of inferior metal.

[2drSE-i]

the book shows an increase of over 150 feet with a failed power booster, the adjustment nut on the back of the booster has nothing to do with the pedal, it's to set the pushrod length right on the booster, if this isn't set right, the rear compensating ports in the MC will be blocked.

I'd believe it, I couldn't stop the thing, which is why I parked it until I could buy a booster lol. Pushrod length adjusts the "throw" of the pedal, if you will. Too short, and yes, it blocks the master cylinder and it won't last very long before the brakes completely lock up. Too long, and you get a TON of brake pedal travel before you get brakes. Been there

[lostforawhile]

I'd believe it, I couldn't stop the thing, which is why I parked it until I could buy a booster lol. Pushrod length adjusts the "throw" of the pedal, if you will. Too short, and yes, it blocks the master cylinder and it won't last very long before the brakes completely lock up. Too long, and you get a TON of brake pedal travel before you get brakes. Been there

there is specified gap between the pushrod out of the booster and the rear piston of the master cyl, you can actually use clay or playdough to make an impression and measure it

[2drSE-i]

there is specified gap between the pushrod out of the booster and the rear piston of the master cyl, you can actually use clay or playdough to make an impression and measure it

Clay worked great, Couldn't have told me that before try three though

[cygnus x-1]

Is DOT 5 silicone fluid? If so, what procedure did you use to flush out all the old glycol based fluid?

DOT5 is the silicone stuff and is not compatible with regular glycol based fluid. DOT5.1 is glycol based and looks to have about the same specs as the silicone stuff.

What pad composition would prevent cementite build up and the dreaded front brake wobble at high speed? I've never owned a Honda that didn't do that. Bedding helps, but doesn't eliminate it. I think the OE spec pad composition is just too soft.

There is a good article on the Stoptech website that talks about this.

http://www.stoptech.com/tech_info/wp...rakedisk.shtml

my pedal doesnt feel like its pulsing even under harsh braking conditions there is no wobel even up to 100 mph but it just feels like i have to push down a long way before it starts
to slow me down but i stil have a alot of travel left

So the problem is travel, not stiffness? That's totally different. If the pedal just feels too low, it's a good bet your drums need service. The shoes are supposed to be self adjusting, to compensate for wear, but the mechanism can seize up over time and stop working. The shoes wear very slowly so it can a long time to notice that anything is wrong. The fix might be as simple as blasting the adjustment mecanism with brake cleaner and working it around to loosen it up. Check the service manual for adjustment/overhaul procedures (there should be a link to the PDF service manual in the FAQ sticky thread).

the book shows an increase of over 150 feet with a failed power booster, the adjustment nut on the back of the booster has nothing to do with the pedal, it's to set the pushrod length right on the booster, if this isn't set right, the rear compensating ports in the MC will be blocked.

What book? I don't see anything like that in the service manual.

But for sure, the stock system is not so great without the booster. Last fall when I was working on my ITBs, they would occasionally not close completely, causing a really high idle and low vacuum condition. When this happened the brake pedal would require significantly more force than usual. If you weren't expecting it, it was seriously annoying.

I drove it for a week maybe without the brake booster, and I'm not a weak guy, but I COULD NOT stop the car as fast without the vacuum assist. It takes some pedal mashing, for sure. If anyone were thinking of doing a booster delete, I would suggest a very large master cylinder.

Yeah, you would need to really wail on the pedal.

As far as a booster delete, you would actually need a *smaller* master cylinder to increase braking force. But it's really not that simple. The master cylinder size is dictated by the volume of fluid required by the calipers. The larger the caliper piston size, the more fluid they need, and the larger the master cylinder needs to be. A MC that's too small won't push enough fluid volume and will bottom out before you get to maximum pressure. A MC cylinder that's too big will push enough fluid volume but will take more force to create the same caliper force than a smaller cylinder would. So what you want is a MC that is just big enough to supply the required fluid volume to the calipers, plus a little more for safety.

Once the MC size is set, you use the pedal ratio to determine the pedal force required for stopping. A longer pedal needs less force (from your foot) but uses more travel, where a shorter pedal uses less travel but also creates less force. For manual brake systems the pedal ratio is something like 6:1, whereas for a power brake system it's more like 4:1. The ratio on my Prelude is 4.5:1, which is not good for a manual system.


So in order to do a proper booster delete you need to make up for the lost assist in some way. I'm doing this by first upgrading to larger calipers (more clamping force) and rotors (more leverage) so that it takes less brake line pressure to create the same stopping force. The MC is then upsized to match the larger calipers, but no more. And finally the pedal ratio is increased for more leverage against the MC. To do that I made a pair of mounting plates that move the MC up closer to the brake pedal fulcrum point. The MC actuator rod will also attach to the pedal closer to the fulcrum point. The master cylinder will be changed to a 15/16" bore model from a 2g Integra. The calipers are from a 2g Integra (front) and 4g Accord (rear). The front rotors go from 9.4" to 11", and the rear rotors go from 9.4" to 10.3". The parts are sized so that the front rear bias is close to stock so there should be no need to change the proportioning valve.
At least that's the hope.


C|

[cygnus x-1]

[Double post due to forum software lameness]

[2ndGenGuy]

I was thinking something along the lines of adjustment of the rear brakes as well. I found out the 1g Accords were manual adjusting, and once I adjusted them, pedal feel was increased tons. Most of the slack was gone... And I know those auto adjusters have a tendency to not work all that well, so some manual intervention may have been required.

[2oodoor]

^^^ he said manual intervention required


woot

[cygnus x-1]

Oh, here's something easy thing you can try. The automatic adjuster only works if you occasionally use the brakes with the car moving backwards. If you never do any significant braking while in reverse, the pads may never adjust. Try driving short distances forwards and backwards, each time applying firm brake pressure to stop the car. It shouldn't take more than two or three tries to work.

If still no change then go for the "manual intervention".


C|

[lostforawhile]

there is a slot in the back of each drum backing plate, you stick a brake spoon in there and turn the pawl with it to adjust

[DBMaster]

you can get brembo rotors for this car, even Honda uses them stock now, there really is a difference, it's all in the metallurgy of the rotor, a lot of big box store rotors are chinese and made of inferior metal.

I have seen you recommend Beck Arnley parts before. The rotors I put on were Beck Arnley "premium" that I picked up as factory closeouts on Rock Auto. I bought them a year before I needed them because the price was so good ($12 each). I hope they turn out to be good, but if they develop pulsation again I will replace them with the Brembos.

[lostforawhile]

I have seen you recommend Beck Arnley parts before. The rotors I put on were Beck Arnley "premium" that I picked up as factory closeouts on Rock Auto. I bought them a year before I needed them because the price was so good ($12 each). I hope they turn out to be good, but if they develop pulsation again I will replace them with the Brembos.

i've had pretty good luck with Beck Arnley stuff in the past most of it seems to be a bit above the box store parts

[Ichiban]

If you are going to do a manual brake conversion, I recommend you do a full self-energizing drum conversion. This way, the entire system can be as pointless, backwards and stupid as possible. Besides, all those rear disk swap people are just throwing their drum brakes in the garbage, so it won't just be cheap, it could be free!!1