Before I ask my question I just want everyone to know that i did search and the answers I found varied so I am starting a new thread lol

I have a 88 HF with a Rear disc conversion. The car came with it converted when I bought it.

It had the factory prop valve on it so I bought a 4040 valve which i haven't installed yet.

Can I get away with installing the prop valve and the Master cylinder from a 90 civic ex?

I read in some threads that if I use the 4040 valve i have to upgrade the front rotors to match.

I am not opposed to doing that, but what rotors and calipers should I get?

Also with the brake booster can I use the stock one with the 90 civic master cylinder or is it recommended to go with a different booster/mc combo???

any help is much appreciated.

 

 

All damn hf knuckles are different?? When i ordered new wheel bearings and ball joints they were the same part number for si dx and hf.. hmm

 

yes knuckles are different, and if you swap them you will need to swap axles.

 

I dot think it's a need to upgrade the prop valve or mc just because you won't be planning on swapping front brake set up, but if you upgrade you would need axles from the car you took them from and depending on which mc you have you not need to change it.

 

You only need the MC if you get bigger front brakes.

- 54mm pistons uses 7/8" MC
- 57mm pistons = 15/16" MC
- 57mm pistons + functioning ABS = 1" MC

That's all there is to it.

 

Thanks for the info everyone... The car has a b16 in it so it possible that its actually a dx??? I was guessing it was an hf.. how can i tell??

 

I would think by the vin number, but I don't know. My shop manual is a UK version so I couldn't tell you the actual US codes.

 

Yea the vin would make sense wouldnt it... Thats what happens when i respond to posts 5 min after waking up lol

 

Ok so it turns out that my car is a DX.. so now that I know that what would be a good front brake option for me that bolts up without modification.

 

ex fronts

 

which years?

 

90/91

 

Da fronts also work. I just used them.

 

If you can give a **** less about suspension geometry, yes they will.

 

A little negative camber doesn't hurt. And if you can't stand that then a camber kit fixes it.

 

Seems crazy to me that the sedan came with better brakes than the crx lol... the 90/91 require no modifications either??

sorry about so many questions i just wanna make sure Im 100% certain before I spend money

 

Both the EX Sedan and the CRX Si got brake upgrades in 1990. The EX has bigger front brakes though because it weighs a lot more.

 

It adds positive camber, not negative.

The sedan weighs MORE than the CRX, it wasn't needed for Honda to put larger brakes on a smaller car for obvious reasons.

The si only got rear discs, it never received a front brake upgrade.

 

Correction not all Si's came with the brake upgrade.

 

In 1990 the CRX Si got larger 54mm caliper pistons and a 7/8" master cylinder to match. The caliper was like a smaller version of the Integra caliper. Also the rotors went up 2mm taller, but 2mm thinner. Some parts databases show the Civic Si got the same front brake treatment in 1990. But when I look at the part numbers on a Honda website, they are the same as 88-89.

88-89 CRX Si caliper:


90-91 CRX Si caliper: