16 replies to this topic

[MinkelR]

So we just did a whole brake overhaul on my friend's '87 HF. It was a no-runner when he got it so we never tested out the brakes as is. We got rid of the worn front brakes and swapped over the Integra front rotors and calipers, replaced the shoes, springs and wheel cylinders (both were very leaky) in the rear. We bled out the old water soaked fluid with some new DOT-3.
The thing stops on a dime and is able to lock up all 4 tires but the brake pedal height seems off. It seems that the brakes don't engage until half the pedal is pushed down and will continue to travel near the floor.
We thought this was a master cylinder problem so we went and got another one and figured we should swap in the larger 4-door 4-speed/PS brake booster as well. Got everything installed and bled out and still the same issue.
I'm totally confused as to what's going on as there is very little left in the brake system that hasn't been replaced, it's been bled multiple times. Should I install the Integra master cylinder? Is the stock MC having difficulties pushing the increased quantity of fluid that the front teg calipers need?

Thanks for the help in advance!

Ryan

[anjin]

Have you checked the brake pedal to master cylinder piston adjustment. You can wind the master cylinder piston in and out - or you could on the set I did a year or so ago. That might do some nice things. A pain to get to. Dropping the steering column down can help in getting access.

[cbstdscott]

If adjusting the brake pedal piston does not work, then it is the brake booster that needs replacing.

Scott

[rpr]

I believe it's more likely that the Integra caliper piston bores are larger than the CRX, so you need to push more fluid to them, hence the longer pedal travel. That's why I use 2G CRX calipers, same piston bore as the 1G.

[cbstdscott]

I believe it's more likely that the Integra caliper piston bores are larger than the CRX, so you need to push more fluid to them, hence the longer pedal travel. That's why I use 2G CRX calipers, same piston bore as the 1G.

I did not have this experience with Integra calipers and the EDM/JDM 1.6/16 CRX use the same Integra calipers/rotors.

I am going out on a limb and declare that this is a brake booster issue. Re built brake boosters are available from most parts stores.

Scott

[MinkelR]

Thanks for the suggestions guys.
It's not that the brake pedal is hard to push down it just begins down low. This is brake booster #2 as well. Should I check the check valve on the booster line?

I have a teg mc laying around somewhere. If that doesn't work I guess I'll go grab another brake booster. Maybe a pedal adjustment in there somewhere too.

[TexanIdiot25]

FWIW, the larger EF calipers that I put onto my HF before I sold it also seemed to have larger pistons. No noticeable difference in pedal feel.

[DEIVIONCRX]

The 1g Integra calipers have larger pistons, thus why the 1g Integra uses a 7/8" Bore master cylinder. Stock Civic/CRX master cylinders are 13/16".

On the same note the 88-89 CRX Si uses the 13/16" master cylinder, the 90-91 CRX Si uses the 7/8"

So if your going to use the 86-89 Integra or 90-91 CRX Si calipers, you need the 7/8" master cylinder, the 85 Prelude Carburated master cylinder bolts on and is 7/8"

[Interceptor]

Is the Master Cylinder installed bolt-on too ?

[Screech]

Is the Master Cylinder installed bolt-on too ?

From the 85 Prelude Carburated, yes. From an Integra, no.

[JamesL]

I believe it's more likely that the Integra caliper piston bores are larger than the CRX, so you need to push more fluid to them, hence the longer pedal travel. That's why I use 2G CRX calipers, same piston bore as the 1G.

^^ I would wager a guess that this is the exact cause.

When I swapped over to the RSX-S brake setup(front/rear) on my EM2 track car, at first I attempted to utilize the OEM 7/8" master cylinder that came with my car. This caused a very noticeable increase in brake pedal travel. So much so that I could no longer effectively heel-toe while on track. The solution was to move to the OEM 15/16" MC from the RSX-S. It cut the pedal travel roughly in half. And made for far more confidence inspiring brake feel.

Also, Im not sure how the piston bores (fr/rear) differ between the Integra calipers and the 1G calipers... but if you have changed both front and rear(or moved from rear drums to discs), you will probably want to move to the Integra proportioning valve as well. Again, I initially retained the OEM prop valve in my track car after I did the brake swap. The EM2 comes from the factory with drums in the rear... Drums apparently require more fluid to activate than discs of comparable design. Thus, wiht the stock proportioning valve/MC and the new front/rear discs, I ended up with a very "rear biased" brake setup. Under heavy braking on track, the rear end would try to come around on me. Very disconcerting when you are braking from 125mph coming off the straightaway.

Using the prop valve from the RSX-S rectified that problem as well.

[rustycivic]

The 1g Integra calipers have larger pistons, thus why the 1g Integra uses a 7/8" Bore master cylinder. Stock Civic/CRX master cylinders are 13/16".

On the same note the 88-89 CRX Si uses the 13/16" master cylinder, the 90-91 CRX Si uses the 7/8"

So if your going to use the 86-89 Integra or 90-91 CRX Si calipers, you need the 7/8" master cylinder, the 85 Prelude Carburated master cylinder bolts on and is 7/8"

so to properly do a integ brake conversion on a 1g crx you need to get the master from the lude?

[1985 CRX SI]

Some times the rear drum brakes can be adjusted to take up alot of this pedal movement.
Jeff

[cbstdscott]

so to properly do a integ brake conversion on a 1g crx you need to get the master from the lude?

No, the stock MC works fine with the Integra front brakes.

As mentioned, check the rear shoes for proper adjustment. If they are not adjusted properly, you will get a lot of pedal travel.

Has the OP checked the brake booster yet? This is a wear item that will need replacement at some point in an old car's life.

Scott

[Aren D.]

What do you "check" on the booster?

Really I have no idea and would like to inspect mine.