Suspension, Steering and Brakes Tourer Rear Calipers AGAIN!

Discussion in '7th Generation (2003-2008) [Acura TSX]' started by Dave, Saturday 12th Mar, 2016.

  1. Dave Expert Advisor ★ ★ ★ ★ ★

    A few years ago I replaced both rear calipers due to them seizing up and last night I got home with a glowing red disc :Frown: I've had discs and pads for a while as they've not been changed for a while hoping maybe I had seized pads or sliders unfortunately not piston seized solid in the caliper!

    I suppose it's to be expected after all the car sits for 5 days a week outside I stripped caliper down and the corrosion is bad inside the seal the piston has hardly any marks on it.

    Off to Euro Car Parts for another one :Frown:
  2. Dave Expert Advisor ★ ★ ★ ★ ★

    All fixed now and changed brake fluid and bled front and rears luckily it was a nice day for it!
    Ichiban likes this.
  3. Bounder Club Member ★ ☆ ☆ ☆ ☆

    Ireland Huan County Cork
    Do you grease the piston and inside the caliper seal locating grooves with red rubber grease?
    It doesn't react with brake fluid as its made from a vegetable base not mineral oil.
    It may help stop them corroding.
  4. Dave Expert Advisor ★ ★ ★ ★ ★

    No I've never done that that's where the corrosion was where the seal goes into the caliper and in between that and the other rubber seal inside the caliper.
  5. Bounder Club Member ★ ☆ ☆ ☆ ☆

    Ireland Huan County Cork
    Worth trying with silicone or RRG, might just stop the corrosion happening as frequently.
    Zebster likes this.
  6. moi Club Member ★ ☆ ☆ ☆ ☆

    United Kingdom london
    Isn't the corrosion largely a result of infrequent brake fluid changes?
  7. Dave Expert Advisor ★ ★ ★ ★ ★

    Usually yes but my car stands outside 7days a week and doesn't move for 5 days in a row so that's probably going to have something to do with it. Brake fluid has been changed regularly and even when I did it this time on all 4 calipers it was as clean as what went in.
  8. Bounder Club Member ★ ☆ ☆ ☆ ☆

    Ireland Huan County Cork
    In my experience brake fluid changes don't have as much effect on corrosion as prepping the caliper properly.
    The pistons seize because corrosion behind the seals grows and pushes the seal inwards, increasing pressure on the piston and making it slow to retract.
    I've done plenty of caliper refurbs over the years on bikes and cars and when you use a compatible grease behind the seals it prevents water from lodging there and starting the process.
    I have found it very hard to remove the crystalline corrosion in those grooves when wet, my tip is to carefully wash the caliper out and use a blowtorch or hot air gun to dry the caliper, once its dry the caliper can be cleaned with scouring pad or similar and the dust from it can be blown out easily, then greased with RRG or Silicone grease and rebuilt.
    I have a rear brake disc and pad set on the way and will be doing a refurb this week. I'll try and get some photos and do a DIY.
    hondream, Dave and SpeedyGee like this.
  9. SpeedyGee Administrator Staff Team

    England Speedy Birmingham
    Look forward to the DIY Guide @Bounder :Thumbup:
  10. Dave Expert Advisor ★ ★ ★ ★ ★

    One thing to point out is that if your pads are a tight fit pop off the stainless bits they sit into in the carrier and clean all the rust off then they will move freely
    Nels and SpeedyGee like this.
  11. Bounder Club Member ★ ☆ ☆ ☆ ☆

    Ireland Huan County Cork
    Today was a National holiday. St Patricks day, I took the opportunity to strip my rear calipers and rebuild them.
    new pads and discs as well,
    There are plenty of guides here about removing and replacing pads but I was actually rebuilding the calipers and I took a few pics to show what yours may look like.
    Disclaimer, working on brakes needs to be done properly and I don't take any responsibility for anything that may happen to you if you get it wrong.
    If you are not confident working on the inside of a brake caliper then get a professional to do the work or just buy new/recon calipers and fit them.
    Inside the caliper is a piston which is sealed by a square O-ring and a Dust seal which is part of the flexible boot that protects the piston from water or dust.
    I removed the disc, caliper and carrier and while the caliper was off I used the brake pedal to pump the piston out of the caliper.
    The piston doesn't have to come all the way out of the pot but enough that you can grip it to wiggle it out.

    A handy tip is if you don't have a special piston puller or piston puller pliers is to use two ring spanners with a 15° angle on the ring ends and insert them into the piston and then simply squeeze the spanners together and the ring ends will grip the piston and allow you to pull it free.
    The dustboot top edge can be popped out of the groove and allowed to slide down the piston as shown.
    This is easier to do off the car so take the opportunity to undo the banjo bolt on the back of the caliper pot.
    Once you have the piston out the pot will be available to inspect drain the old brake fluid into a container for inspection and disposal.
    You can see the sorry condition of the fluid inside the caliper in this photo.

    I wipe the inside of the caliper out with a rag and then pick the sealing o-ring out carefully with a pick, then the dustboot can be popped out of its groove as well, mine was stuck in place with rust so I had to be very careful not to damage it by injudicious pulling, once a small part of it is free the rest will follow pulling inwards.
    You can see that corrosion has taken a firm hold on the surfaces that hold the seals but all is not lost.
    and the caliper is still salvageable.
    ideally you will have a caliper refurb kit to replace the seals and boots and possibly pistons if necessary but in my case I carefully cleaned and reused the seals.
    The piston was cleaned with a rag and some penetrating oil to remove the old grease and then a brass wirebrush was used to clean the remaining deposits on the piston,
    Finally a strip of 1200 grit wet and dry was used with the piston gripped carefully in a vise to polish the pitted areas.
    These look bad but are very smooth.
    The caliper cleaned up quite well, with a small scraper to remove the heavy stuff and a good wirebrushing.
    The grooves were liberally smeared with red rubber grease and the old seals carefully refitted.
    At this point my hands were covered in grease rust and brake fluid so I wasn't able to take any more pics but the last one shows the inner seal fitted and the caliper is ready to have the outer boot fitted on the piston and then installed.
    DSCF3129_1024x768.JPG DSCF3129_1024x768.JPG
    One tip I use is to use a plumbers blowtorch to heat the caliper once all rubber parts are off, this dries the old brake fluid and allows you to wirebrush and clean the caliper effectively instead of dealing with rusty brake fluid. if you do use this method don't keep a finger over the hole where the banjo bolt screws in while you play the blowtorch over the inside of the caliper. It will burn the finger through the small hole

    Attached Files:

    Zebster likes this.