Spongy Pedal and Poor Brakes

Discussion and technical advice for 84-89 AW10 & AW11 MR2. 3A-LU, 4A-GE, 4A-GZE.

Moderators: IMOC Moderators, IMOC Committee Members

System-G
Posts: 4554
Joined: Tue Dec 28, 2004 10:50 am
Location: Leicestershire

Re: Spongy Pedal and Poor Brakes

Post by System-G »

Bender Unit wrote:
When bleeding start off with the brake nearest the servo and then work your way around, doing the furthest away last.


Erm... No.

Always furthest fromthe master cylinder 1st and work to the nearest :thumleft:

If you are genuinely concerned about air still being trapped in the system, find something to wedge the brake pedal down overnight. It's a sort of "self-bleed" - works especially well if air is trapped in the master cylinder.

Also avoid those Ezibleed kits - rubbish. Although the tubes are usefull when bleeding old school :mrgreen:
Just don't rely on the "oneway" valves.
85 MK1 MR2 Track N/Ail | 99 528i SE Touring | 01 Mandarin VX220
Mr_Spanners
Posts: 121
Joined: Tue Apr 08, 2008 8:15 pm
Location: Ashton-Under-Lyne

Re: Spongy Pedal and Poor Brakes

Post by Mr_Spanners »

System-G wrote:
Bender Unit wrote:
When bleeding start off with the brake nearest the servo and then work your way around, doing the furthest away last.


Erm... No.

Always furthest fromthe master cylinder 1st and work to the nearest :thumleft:

If you are genuinely concerned about air still being trapped in the system, find something to wedge the brake pedal down overnight. It's a sort of "self-bleed" - works especially well if air is trapped in the master cylinder.

Also avoid those Ezibleed kits - rubbish. Although the tubes are usefull when bleeding old school :mrgreen:
Just don't rely on the "oneway" valves.


Yeah, I missed that piece of mis-information - I always bleed from the furthest caliper from the reservoir! I will try the prop on the brake pedal overnight too.... I'm still baffled by the fact that the pedal pumps up really hard when the car isn;t running but goes really soft and spongy when it is.... could it be a faulty servo??? Must double check that vacuum hose!!!
System-G
Posts: 4554
Joined: Tue Dec 28, 2004 10:50 am
Location: Leicestershire

Re: Spongy Pedal and Poor Brakes

Post by System-G »

If the servo vaccume hose is leaking or disconnected, the pedal will feel hard as, but no response from the brakes.
85 MK1 MR2 Track N/Ail | 99 528i SE Touring | 01 Mandarin VX220
MartG
Posts: 6029
Joined: Thu Apr 07, 2005 2:19 pm
Location: Poulton le Fylde, Blackpool
Contact:

Re: Spongy Pedal and Poor Brakes

Post by MartG »

Mr_Spanners wrote:I'm still baffled by the fact that the pedal pumps up really hard when the car isn;t running but goes really soft and spongy when it is.... could it be a faulty servo??? Must double check that vacuum hose!!!


Just shows that the servo is working, allowing more pressure to be put on the master cylinder
LimeyMk1
IMOC Committee
Posts: 11200
Joined: Thu Oct 04, 2007 9:28 am
Location: Gosport

Re: Spongy Pedal and Poor Brakes

Post by LimeyMk1 »

System-G wrote:Also avoid those Ezibleed kits - rubbish. Although the tubes are usefull when bleeding old school :mrgreen:
Just don't rely on the "oneway" valves.


:lol: They're not that bad G, altho I must admit I still leave the end submerged in brake fluid. 8-[
millentubby
Posts: 871
Joined: Mon Nov 28, 2005 4:29 pm
Location: Edinburgh

Re: Spongy Pedal and Poor Brakes

Post by millentubby »

I've just finished a major brake overhaul on a customers mk1;

New discs + pads all round,
Calipers stripped, painted and rebuilt with new seals all over,
Goodridge Stainless Braided Hoses,
New DOT4 Brake Fluid.

After the second bleed I was severely disappointed with the feel of the brakes...so bled again and it was superb.

Remember to instruct your mate to depress and release the brake pedal smoothly and slowly and bleed the furthest caliper from the MC first - working your way in order of distance from the caliper. (On mk1 mr2 start with Rear-Left, then Rear-Right, then Front-Left, then Front Right).

EDIT - no offence...but do a quick numpty-check and make sure you've put the calipers onto the correct sides of the car; if they're mixed up the bleed nipples will be at the bottom and the air will struggle to leave the calipers!
Cyman LeBon

New Battery not holding charge

Post by Cyman LeBon »

Hello all,
Bought a new battery for my 1990 MK1 and it is not holding charge. I am assuming the alternator is not working as the car needs a jump start but will not start then after a few days and a good spin. Thought the Alarm might have been running the battery flat but even with it off it is still not right. Just wondering how I will check if the alternator is working or does anyone have any other suggestions?

Thanks,
Cyman :thumleft:
Mr_Spanners
Posts: 121
Joined: Tue Apr 08, 2008 8:15 pm
Location: Ashton-Under-Lyne

Re: Spongy Pedal and Poor Brakes

Post by Mr_Spanners »

millentubby wrote:I've just finished a major brake overhaul on a customers mk1;

New discs + pads all round,
Calipers stripped, painted and rebuilt with new seals all over,
Goodridge Stainless Braided Hoses,
New DOT4 Brake Fluid.

After the second bleed I was severely disappointed with the feel of the brakes...so bled again and it was superb.

Remember to instruct your mate to depress and release the brake pedal smoothly and slowly and bleed the furthest caliper from the MC first - working your way in order of distance from the caliper. (On mk1 mr2 start with Rear-Left, then Rear-Right, then Front-Left, then Front Right).

EDIT - no offence...but do a quick numpty-check and make sure you've put the calipers onto the correct sides of the car; if they're mixed up the bleed nipples will be at the bottom and the air will struggle to leave the calipers!


Thanks! The calipers are the right way up and like you, I've bled the car twice (having replaced the fluid) but I'm going to do it again with the engine running to see if that helps (I'll have the car up on 4 axle stands). I'm going to bleed the master cylinder too if bleeding at the calipers fails to improve matters.

Will report back!

~Phil.
Kooga
Posts: 577
Joined: Sun Mar 20, 2005 10:06 pm
Location: Rayleigh, Essex

Re: Spongy Pedal and Poor Brakes

Post by Kooga »

Apologies if this is teaching you to suck eggs....I'm not sure how you are carrying out your bleeding, but are you closing off the bleed nipple after every down press on the pedal? This is the only 100% successful way I've found of doing this. Open nipple, press pedal down, close nipple, release pedal, repeat until fluid lovely and clear...definitely a 2 person job unless you have a pressure bleed tool...
Mr_Spanners
Posts: 121
Joined: Tue Apr 08, 2008 8:15 pm
Location: Ashton-Under-Lyne

Re: Spongy Pedal and Poor Brakes

Post by Mr_Spanners »

Kooga wrote:Apologies if this is teaching you to suck eggs....I'm not sure how you are carrying out your bleeding, but are you closing off the bleed nipple after every down press on the pedal? This is the only 100% successful way I've found of doing this. Open nipple, press pedal down, close nipple, release pedal, repeat until fluid lovely and clear...definitely a 2 person job unless you have a pressure bleed tool...


Yes, that's what I'm doing - I'm also using a bleed tube submerged in a jar that has brake fluid in so no air can get in! I'm hopeful that another round of bleeding with the engine running sorts out the probelm.
Kooga
Posts: 577
Joined: Sun Mar 20, 2005 10:06 pm
Location: Rayleigh, Essex

Re: Spongy Pedal and Poor Brakes

Post by Kooga »

I used alot of fluid getting mine clear, most of a litre to do all 4. I've fitted braided hoses and DOT 5.1 on mine which has made a massive difference to the pedal feel, always thought it was a bit spongy as std, even though it had no air in...
System-G
Posts: 4554
Joined: Tue Dec 28, 2004 10:50 am
Location: Leicestershire

Re: Spongy Pedal and Poor Brakes

Post by System-G »

Also something else I've remembered.

If you push the pedal to the floor when bleeding, there is a chance that you could damange the master cylinder or seals on the piston. This happened with my old 1a master cylinder.
85 MK1 MR2 Track N/Ail | 99 528i SE Touring | 01 Mandarin VX220
Mr_Spanners
Posts: 121
Joined: Tue Apr 08, 2008 8:15 pm
Location: Ashton-Under-Lyne

Re: Spongy Pedal and Poor Brakes

Post by Mr_Spanners »

Quick update - the car is sorted!!! \:D/

Needed bleeding 3 full times with the engine running to sort it. Amazed that I'd bled it already (3 times on each caliper) without the engine running and when I tried the first time with the engine the amount of air that came out of the rear calipers was incredible!!! :shock:

So, if you're bleeding the brakes on a Mk1 do it with the car running (and safely up on 4 axle stands!)

Thanks to all the people who offered help and advice!!!

Cheers,

~Phil.
MartG
Posts: 6029
Joined: Thu Apr 07, 2005 2:19 pm
Location: Poulton le Fylde, Blackpool
Contact:

Re: Spongy Pedal and Poor Brakes

Post by MartG »

Glad to hear it's sorted :thumleft:
Paff
Posts: 59
Joined: Tue Aug 30, 2005 7:38 pm

Re: Spongy Pedal and Poor Brakes

Post by Paff »

strange to have to hae the engine running, I've never done it that way and never had a problem. And I've worked on quite a lot of mk1's now.
Paff
Posts: 59
Joined: Tue Aug 30, 2005 7:38 pm

Re: Spongy Pedal and Poor Brakes

Post by Paff »

oh, glad its sorted tho :)
mr2mk1chick
Posts: 4079
Joined: Tue May 24, 2005 11:53 am
Location: Leicester

Re: Spongy Pedal and Poor Brakes

Post by mr2mk1chick »

Paff wrote:strange to have to hae the engine running, I've never done it that way and never had a problem. And I've worked on quite a lot of mk1's now.

The engine running may just be coincidental, as they are/can be a pig to bleed - as many people have pointed out take a fair few attempts too.
Glad its all sorted :thumleft:
Image
coverco
Posts: 1489
Joined: Mon Mar 20, 2006 6:31 pm

Re: Spongy Pedal and Poor Brakes

Post by coverco »

Mr_Spanners wrote:Quick update - the car is sorted!!! \:D/

Needed bleeding 3 full times with the engine running to sort it. Amazed that I'd bled it already (3 times on each caliper) without the engine running and when I tried the first time with the engine the amount of air that came out of the rear calipers was incredible!!! :shock:

So, if you're bleeding the brakes on a Mk1 do it with the car running (and safely up on 4 axle stands!)

Thanks to all the people who offered help and advice!!!

Cheers,

~Phil.


Well done Phil, now the brakes are right you can come to Tatton at the end of May, my car is going back on the road on the 1st April, I can't wait :thumleft:
System-G
Posts: 4554
Joined: Tue Dec 28, 2004 10:50 am
Location: Leicestershire

Re: Spongy Pedal and Poor Brakes

Post by System-G »

Paff wrote:strange to have to hae the engine running, I've never done it that way and never had a problem. And I've worked on quite a lot of mk1's now.


Likewise. And like Jo said, I think it's coincidental too :thumleft:
85 MK1 MR2 Track N/Ail | 99 528i SE Touring | 01 Mandarin VX220
Mr_Spanners
Posts: 121
Joined: Tue Apr 08, 2008 8:15 pm
Location: Ashton-Under-Lyne

Re: Spongy Pedal and Poor Brakes

Post by Mr_Spanners »

coverco wrote:
Well done Phil, now the brakes are right you can come to Tatton at the end of May, my car is going back on the road on the 1st April, I can't wait :thumleft:


'Fraid the car goes to its new home in the next week or two. A good friend is looking after her so I promised to get the brakes (and a few other bits and bobs done) before I wave goodbye!

Will try and make it to Tatton anyway - I now have a very nice DC2 Integra as my 'toy' so if MCR-VTEC book a plot I'll be 'on site'!!! 8)
Post Reply

Return to “MR2 MK1 1984-1989 NA & SC”