Brake servo refurbishment

[Wiggins]

Hey guys,

I've not owned my DC5 for much more than a year and every time I drive it I think the brakes are appalling, I have to push soo hard on the pedal to pull up. I've done all the obvious things (leak checks, bleeding, refurbed callipers), I've checked the check valve and vacuum pressure (15Hg). I've carried out the master cylinder and servo tests in the manual and I found them all to be a pass. The only thing that I notice that doesn't seem right is that I get a hissing/foot pump noise when I depress the pedal so I think the servo's had it.

I've checked with Honda and trolled the net for a new one and for a service kit. I can't find a service kit and Honda don't sell the servo anymore. The only place I can see one is amayama.com and though I've bought parts from them before they do have some pretty crappy reviews (2.9 on trustpilot). Does anyone know somewhere that sells a new servo or somewhere that can service the one I have?

I plan to service the BMC while I've got it off the car and, as I expect this repair to drag out a little, I plan to fit braided lines and a Tegiwa brake stopper. I just think the brakes are that bad that I don't really expect the new lines and stopper to have the desired affect. Any other suggestions would be greatly appreciated. Thanks in advance.

George W

 

[James-T]

What pads do you have fitted?

 

[carl hammond]

Hey guys,

I've not owned my DC5 for much more than a year and every time I drive it I think the brakes are appalling, I have to push soo hard on the pedal to pull up. I've done all the obvious things (leak checks, bleeding, refurbed callipers), I've checked the check valve and vacuum pressure (15Hg). I've carried out the master cylinder and servo tests in the manual and I found them all to be a pass. The only thing that I notice that doesn't seem right is that I get a hissing/foot pump noise when I depress the pedal so I think the servo's had it.

I've checked with Honda and trolled the net for a new one and for a service kit. I can't find a service kit and Honda don't sell the servo anymore. The only place I can see one is amayama.com and though I've bought parts from them before they do have some pretty crappy reviews (2.9 on trustpilot). Does anyone know somewhere that sells a new servo or somewhere that can service the one I have?

I plan to service the BMC while I've got it off the car and, as I expect this repair to drag out a little, I plan to fit braided lines and a Tegiwa brake stopper. I just think the brakes are that bad that I don't really expect the new lines and stopper to have the desired affect. Any other suggestions would be greatly appreciated. Thanks in advance.

George W

Firstly as James has said what pads are you running? also braided lines will help but they wont fix it as I have never experienced anything like what you're having even when I was running a complete oem brake setup (pads, lines, fluid etc).

The Tegiwa brake stopper (imo) is a waste of time and money, wont be of any real benefit, you're better off finding the issues, resolve that and then if you'renot happy get decent pads, braided lines and decent fluid in there.

For example I am running oem calipers, Project Mu HC80+ pads, Hel braided lines and RBF660 fluid and it's great (the pads are not really for road use as really have to be up to temp) but for road you could use Dixel ES which are a very good road and occasional track pad where they can easily copy with shorter sessions.

Andy (Integrastella may have the part you need) he is on facebook, I cant give his personal number out but if you are on there or ebay look for Integrastella and he may be able to supply a second hand part of what you need.

Is the master cylinder ok as that's the only thing that ever failed on my brake system, one of the three bolts holding the side panel on literally snapped itself and so the fluid was leaking out, before this I noticed the brakes worsening a bit.

Carl

 

[Wiggins]

Firstly as James has said what pads are you running? also braided lines will help but they wont fix it as I have never experienced anything like what you're having even when I was running a complete oem brake setup (pads, lines, fluid etc).

The Tegiwa brake stopper (imo) is a waste of time and money, wont be of any real benefit, you're better off finding the issues, resolve that and then if you'renot happy get decent pads, braided lines and decent fluid in there.

For example I am running oem calipers, Project Mu HC80+ pads, Hel braided lines and RBF660 fluid and it's great (the pads are not really for road use as really have to be up to temp) but for road you could use Dixel ES which are a very good road and occasional track pad where they can easily copy with shorter sessions.

Andy (Integrastella may have the part you need) he is on facebook, I cant give his personal number out but if you are on there or ebay look for Integrastella and he may be able to supply a second hand part of what you need.

Is the master cylinder ok as that's the only thing that ever failed on my brake system, one of the three bolts holding the side panel on literally snapped itself and so the fluid was leaking out, before this I noticed the brakes worsening a bit.

Carl

I'm running OEM calipers Ferodo DS2500 pads on front and EBC Green on rear. I have Hel braided lines to go on but at the moment they're OEM and I think the fluid's just standard DOT4, does the RBF 660 really make a difference? Might have to get me some of that for when I fitted the braided lines ect.

I'm not all that keen to get a second hand one as the only reason I suspect BMC and servo to be a problem is 1. the hissing/ foot pump noise I mentioned previously and 2. just the pure fact of their age, I would imagine that after 17yrs the rubber components in these 2 assemblies would start to break down and need replacing entirely.

From my symptoms, I'm not actually sure which assembly to point the finger at. I'm debating whether not I just fitted the parts I have and service the BMC and then see how I feel. As there is some corrosion under on the front of servo but it's difficult to tell whether or not it's water coming in from the wheel arch or brake fluid from the BMC. Also strangely I have to over torque the bleed nipples on front to 17Nm to stop them from leaking fluid so I guess there's potential for leaky nipples but I don't see any fluid there or notice my resy level dropping.

Symptoms are:

Travel in pedal/low biting point
Almost spongey/air feel - I have to push really hard to get the desired affect
Hissing/foot pump noise when depressing the pedal

 

[carl hammond]

I'm running OEM calipers Ferodo DS2500 pads on front and EBC Green on rear. I have Hel braided lines to go on but at the moment they're OEM and I think the fluid's just standard DOT4, does the RBF 660 really make a difference? Might have to get me some of that for when I fitted the braided lines ect.

I'm not all that keen to get a second hand one as the only reason I suspect BMC and servo to be a problem is 1. the hissing/ foot pump noise I mentioned previously and 2. just the pure fact of their age, I would imagine that after 17yrs the rubber components in these 2 assemblies would start to break down and need replacing entirely.

From my symptoms, I'm not actually sure which assembly to point the finger at. I'm debating whether not I just fitted the parts I have and service the BMC and then see how I feel. As there is some corrosion under on the front of servo but it's difficult to tell whether or not it's water coming in from the wheel arch or brake fluid from the BMC. Also strangely I have to over torque the bleed nipples on front to 17Nm to stop them from leaking fluid so I guess there's potential for leaky nipples but I don't see any fluid there or notice my resy level dropping.

Symptoms are:

Travel in pedal/low biting point
Almost spongey/air feel - I have to push really hard to get the desired affect
Hissing/foot pump noise when depressing the pedal

From that it sounds like the Master Cylinder, they have been known to go on a few and there are two designs (one has 3 security hex bolts on the side holding it together) the other is a sealed unit. Mine was the hex one and broke, luckily I was at a services on the way home, pulled in for a break, got in the car Clutch down to start and bang it failed (literally a massive bang as the bolt snapped).

Almost spongey/air feel and Hissing/foot pump noise when depressing the pedal are common with master cylinder issues, have you tried to adjust the biting point? that said if it's getting lower then its a sign it's going imo. I would before spending big money on a servo do the following:

Fit the hel braided brake lines
Fill with new fluid (oem if you want or upgrade to RBF600 or 660) depends on how you use and drive the car, I use it as I am tracking my car a lot
Get it bled fully (these are a pain in the backside to bleed), I spend hours trying to get mine right then gave up and got a mate to help as I was getting annoyed with constant air in the system (do you bleed it in the right order) I think it on here somewhere which caliper to do in order etc

The bleed nipple maybe an issue but it could also be backpressure maybe forcing the fluid out and overtightening it is just trying to plug it up so to speak.

I am no brake expert by any means but the symptoms seem likely to me to be the Master Cylinder from experience

I feel at least doing it that way there is no massive additional expense, the max you may have to do it the master is not the issue is then buy new brake fluid and re-bleed the system, which is going to be much cheaper than replacing that if its not needed. I personally don't know of any that have needed that to be replaced but the master and slave have been issue points in the past

Carl

 

[Wiggins]

Thanks Carl and James, I'll service the BMC, fit the braided lines and change the fluid to RBF600 as I only use the car for fast road. Keep you posted on the results.

 

[carl hammond]

Thanks Carl and James, I'll service the BMC, fit the braided lines and change the fluid to RBF600 as I only use the car for fast road. Keep you posted on the results.

Yeah for normal road using etc no harm in going up to that tbh, boiling points higher than oem etc so if you're driving spirited then it would be beneficial, that's imo the best way as no point paying for things you may not need and the cost of a fluid change is far cheaper down the line. The BMC was not that hard to do, I had never done one and needed to but a few tools from memory but it was not that bad. I took the drivers seat out from memory for even easier access to everything

 

[Wiggins]

Ok guys so . . .

I've replaced all the seals in the BMC, replaced all the hard lines (2 back ones split when I was fitting braided hoses), fitted braided hoses to all 4 corners and fitted a second hand ABS as I broke mine (removed the motor cover and broke a spring loaded pin when trying to refit it).

Now I've gone to set the servo pushrod distance and the servo wont hold vacuum, does anyone know if there's an aftermarket/alternative servo that will fit on these cars? (EP3, DC2 ect.)

I don't really want to buy a second hand one from Integrastella as I don't see that the rubber diaphragm is going to last very long.

 

[Jam_DC5]

Ok guys so . . .

I've replaced all the seals in the BMC, replaced all the hard lines (2 back ones split when I was fitting braided hoses), fitted braided hoses to all 4 corners and fitted a second hand ABS as I broke mine (removed the motor cover and broke a spring loaded pin when trying to refit it).

Now I've gone to set the servo pushrod distance and the servo wont hold vacuum, does anyone know if there's an aftermarket/alternative servo that will fit on these cars? (EP3, DC2 ect.)

I don't really want to buy a second hand one from Integrastella as I don't see that the rubber diaphragm is going to last very long.

Hi Mate,

Did you ever find a solution to this issue? I'm having similar symptoms with mine after rebuilding the front calipers and fully bleeding the system. I expected to feel a big difference in firmness on the pedal but it's exactly the same as before, long pedal travel and hard pushing to get them to work properly.

When i was bleeding them i also noticed an odd noise when pressing the pedal so i assume its the same as what you heard.

Wondering whether it's worth just changing the full BMC and servo assembly to rule it all out.

But any info on how you managed to sort it would be great.

Cheers